Many of us have a conflicted attitude towards punctuation. On social media, we tend to enjoy it when friends share humorous pictures of punctuation mistakes. But when it comes to actually studying the rules of grammar, we can be a bit lazy. Intuitively we feel that we know the rules, but most of us end up guessing where a comma or a semi-colon should go. It’s time to change that.

Funny Mistakes

One of the most common punctuation mistakes is to form the plural with an apostrophe. This is sometimes called the “grocer’s apostrophe,” since it seems to happen all too frequently in supermarkets:

Would you have spotted that this should read “bananas”? It’s good to avoid such basic errors, but if we want to improve more substantially, we really need to study grammar.

Sentence Structure

The key to learning punctuation is to understand how the parts of a sentence work together. Take the following sentence:

If you’ve watched enough TV detective series, then you’ll get the impression that the most dangerous places in the world are Oxford, small islands in the Caribbean, and pretty much anywhere in the British countryside.

Why the commas? The first one is to separate the dependent clause (starting with “if”) from the independent clause (starting with “then”). The remaining commas separate the items in a list. People often argue about whether the last one is necessary, given that we’ve already used “and.” The added comma is known as the Oxford comma: it is increasingly preferred, as it provides more clarity.

The point, however, is that knowing something about sentence structure makes punctuation much easier.

The Breathing Theory of Punctuation

What you want to avoid, by contrast, is adding punctuation marks such as commas and semi-colons whenever it sounds like there is a pause. Writing is not like swimming, where you take regular breaths between strokes. It’s quite possible to have an entire sentence without punctuation, other than the initial capital and the final period. Although our pauses and our punctuation marks will often line up, the breathing theory of punctuation is imprecise and best avoided.


There is a real beauty to punctuation. Once you see how the different parts of a sentence work together, you’ll feel more at ease, even with some of the trickier punctuation marks. You might even take pride in being able to use a semi-colon or a dash effectively.



The apostrophe is used to indicate possession (e.g., Tom’s plan, the cat’s whiskers) and to show the omission of letters where a word has been contracted (e.g., I can’t remember the ’80s for I cannot remember the 1980s). In some rare cases an apostrophe can be used to form a plural.


Apostrophes are used to show that a noun or pronoun is in the possessive case. In other words, one thing belongs to another:

Sinbad’s adventures
the constitution’s detractors
a mouse’s tail
the cabin’s porthole
the incumbent’s election strategy

One way to check if you’re dealing with possession is to turn the phrase into an “of” construction:

Sinbad’s adventures = the adventures of Sinbad.

This test also helps us to figure out where the apostrophe goes. When I rewrite the parents of those kids as those kids’ parents, I add the apostrophe after the actual word in the possessive case (not kid’s, but kids’).

Unfortunately, using an of construction works less well when the relationship between nouns is more abstract. This is especially the case when indicating time or quantity:

tomorrow’s agenda
a summer’s day
anyone’s game
a week’s pay
a dollar’s worth

However, if you understand the basic idea of possession, then these outliers will provide little trouble.

Basic rules

Here are the basic rules to show possession.

1. For singular nouns, add ’s:

Eugene’s apple
the tree’s branches
Chris’s homework

2. The same rule applies to plural nouns that don’t end in s:

the children’s toys
the women’s washroom
the moose’s migration

3. However, for plural nouns that end in an s you only have to add the apostrophe:

the horses’ pasture
the siblings’ secrets
the dolphins’ tricks

Tricky cases

Singular nouns that end in s

Most of the time, if a singular noun ends with an s (or sounds like it does) you can safely add the apostrophe and the s:

James’s car
the sax’s mouth-piece
the bus’s colour
the glass’s contents

However, there are a number of exceptions to this rule. In such cases you are encouraged to add only an apostrophe. Although style guides disagree about the details, here are the most common exceptions.

1. When the noun ends with an “us” or “eez” sound:

Jesus’ parables
Socrates’ suicide
Moses’ suspicions

2. When you’re dealing with biblical or classical names (note the overlap with 1):

Euripides’ play
Barnabas’ mission

3. In some for … sake expressions where the noun ends with an s (or sounds like it does):

for conscience’ sake
for goodness’ sake

However, this is not an iron rule for nouns that only sound like they end with an s (e.g., you can write appearance’s sake or appearance’ sake).

4. With nouns that end in s and don’t change their form from the singular to the plural:

many TV series’ ratings (my favourite series’ lead actor)
those species’ survival (that species’ habitat)

5. With names of places, organization, and the like:

The United States’ foreign influence
Step Up For Students’ scholarships

Please remember, though, that these are not hard and fast rules. Grammarians argue a great deal about when you can drop the s and add only the apostrophe. For example, in academic writing the trend is to retain the s after the apostrophe, whereas news publications are more likely to drop it.

If in doubt, you could use an “of” construction instead: the parables of Jesus, etc. This can also makes your writing sound more formal.

Compound Terms

When multiple words are combined in one unit it’s called a compound noun. The apostrophe is added to the last word, even if the compound noun is a plural:

the Governor General’s approval
my sisters-in-law’s holiday plans
everybody else’s homework
my mother-in-law’s criticisms
the commander-in-chief’s cowardice

Group Ownership

Group ownership, or “joint possession,” occurs when something belongs to multiple nouns.

When people own something together, only one apostrophe is needed:

Jerry and Jessica’s dairy farm could be seen from the highway.

When there is no common ownership, you need separate apostrophes:

We admired Elsa’s and Jaspreet’s ultrasounds.

Double Possessives

A double possessive is a phrase that indicates possession twice (by using of and ’s):

a daughter of Mary’s
a painting of Esther’s

If this sounds awkward, just remember that you would say a daughter of mine (where mine is a possessive pronoun) and not a daughter of me. These constructions are typically avoided in formal and academic writing.


In addition to indicating possession, apostrophes show when letters or numbers are omitted. In the case of verbs, the shortened forms sometimes look quite different from the original (the worst offender being ain’t):

don’t = do not
it’s = it is
won’t = will not
William’s late = William is late
shouldn’t = should not
ain’t = am not; are not; is not

Other words can also be shortened using apostrophes:


Apostrophes sometimes show missing numbers:

she grew up in the ’90s (for the 1990s)
we used to own a ’97 Pontiac Montana (for 1997)

In academic writing, contractions are typically written out fully (if the revolutionaries had not … instead of hadn’t). By contrast, the use of slang is often indicated by means of apostrophes (how y’all doin’?).

Finally, in some names the apostrophe appears to indicate a contraction but is actually used to indicate pronunciation, or to tie words together. For example, the apostrophe in the Irish name O’Neill does not indicate omitted letters, because O is an anglicized version of the Gaelic ua, or descendant.

Forming plurals

Normally you should not use the apostrophe to form the plural of a noun. Such a mistake is called “the grocer’s apostrophe,” because of its common occurrence on signs and advertising.

However, an exception is made for the plurals of numbers, letters, symbols, and words referred to as words:

Dot your i’s and cross your t’s
He can count by 1’s and 2’s.
She likes to use &’s in her writing
There are no if’s and but’s about it

(Note that in these cases italics are not used for the apostrophe and the s).

This rule is not applied rigorously though, and in some cases (especially abbreviations) it may be preferable to omit the apostrophe:

Not all PhDs imply high IQs

In fact, in the plural form of decades it is now customary to leave out the apostrophe:

Gutenberg invented his printing press in the late 1430s.

Common errors and ambiguities

It’s / its

If you’re confused about these two, don’t be embarrassed. People often assume that it’s is possessive because the possessive case is typically formed with an ’s. However it’s is a contraction for it is, whereas its shows possession:

It’s almost bedtime. (It is)
The plane made its descent.
A cow chews its cud.
It’s me, silly. (It is)

Place names and businesses

If you like to scour maps, you’ll notice that a lot of place names have dropped their apostrophes. This is especially the case in the US, where the apostrophe is the exception rather than the rule. Thus we have Martha’s Vineyard (which got its apostrophe back in 1933), but also Harpers Ferry. Similar irregularities occur with company names. Compare, for instance, Barclays Bank and Shoppers Drug Mart with Wendy’s or McDonald’s.

Nouns as adjectives

In English, nouns often take on the role of adjectives (e.g., the school play, tunnel vision), in which case there is no need for an apostrophe to indicate possession (not the school’s play or tunnel’s vision). However, in some cases it is difficult to know whether you’re dealing with possession or not:

Is it farmer’s market, farmers’ market, or farmers market? (comp. teacher’s college)

Each version has a slightly different ring. The apostrophe suggests more that the market is owned by the farmers, whereas the adjective form clarifies what kind of market it is. None of these versions is necessarily incorrect, and you will have to balance your own preference with local usage.

Possessive pronouns:

Make sure you don’t use an apostrophe for the following possessive pronouns:

hers, its, theirs, yours, and ours.

On the other hand, indefinite pronouns do take an apostrophe:

one’s, somebody’s, etc.

Last names

Never use an apostrophe for the plural of names. Just add an s or es. The latter is used when the name ends with an s or a similar sound (sh, ch, x, or z):

The Joneses and the Larches played shinny on the frozen pond.
There are three Eriks in Wayside School.

Also, don’t change a final y to ies:

The Trotskys taught the Tracys that sharing is caring.

So when you add the apostrophe to show possession, it looks like this:

The Nguyens’ restaurant was vandalized.
The Smiths’ Lego collection fills the entire basement.

Commas: Major Rules


There are quite a few rules for commas, which is why some people give up in frustration and end up guessing. Yet guessing won’t get you very far.

The good news is that these days there are fairly clear rules for when you should use a comma. If you take your time reviewing the basic patterns and doing the exercises, you will get the hang of it soon enough.

On this page you will find the major patterns for comma usage. For minor uses, please see our separate lesson.

Major Uses

In this section, we will review the following basic patterns:

Major Patterns

Read on to learn more about each rule.

Between independent clauses joined with a coordinating conjunction

Coordinating conjunctions are those seven little words that tie parts of the sentence together: and, but, for, nor, or, so, yet.  If you use one between two independent clauses, then you can place a comma in front of it:

David was looking for his pencil sharpener, but he could not find it anywhere.

Let’s say you’re a feminist, and it is time to vote—do you automatically vote for a female candidate?

Pele is widely considered the greatest soccer player, but you could make the case that Messi and Ronaldo are up there too.

You can relax this rule if the clauses are very short:

He sanded down the coffee table and then he stained it.

You also don’t need a comma if the second clause is missing a subject. In that case the sentence usually has one subject and two verbs:

El Escorial was built by King Philip II of Spain and is both a monastery and a royal palace.

She wants to join the Shriners and wear a fez.

There are no commas in these examples because you don’t want to stick a comma between the subject and the verb.  The exception is if there is a gap of time between the two clauses:

Gilbert gambled, but lost.

Trixie trained for the triathlon, yet never officially raced.

So, as you can see, the basic pattern is clear, but there is some room for discretion.

After an introductory word or phrase

Many sentences start out with an introductory word or phrase. These introductory elements are often separated from the rest of the sentence by a comma:

During the Irish Potato Famine, hundreds of thousands of people emigrated from Ireland.

Unfortunately, the sirocco stirred up a dust storm.

While turning the auger, Britney smoked a great big pipe.

Caught with his pants down, Emerson jumped out of the window.

Sometimes we get several phrases before the comma:

After the start of the Protestant Reformation, Martin Luther’s ideas spread rapidly.

Still, a comma is not always advisable:

Yesterday she was fishing for compliments again.

In the beginning was the Word.

After me you can go.

In other words, it’s a judgment call. If a comma creates clarity then use it. If it interrupts the flow, leave it out.

Between a dependent clause and an independent clause

It’s considered good manners to use a comma after a dependent clause and before an independent clause.

When she marks my essay, she uses red ink the colour of blood.

According to Greek mythology, after Cronos castrated his father Uranus with a sickle, he threw the testicles into the sea.

Here are some more (and less violent) examples:

Whenever Kayla was in a bad mood, Tom told her that he had thoughts of buying her flowers.

Although Pope Joan probably never existed, the idea of a female pope makes for a great story.

If you are baking, can you make brownies?

You can of course relax this rule if the clauses are quite short:

Once you were gone I could not stay.

When summer is over we all go back to school.

On the other hand, if you reverse the order of the sentence and place the dependent clause after the independent clause, then you don’t need a comma. That’s because the conjunction now comes between the clauses and nicely connects them:

I pumped up the tires because they were low.

An Egyptian will have a conniption if you say at his trial that he lives in denial.

Still, you probably won’t be surprised to find out that sometimes a comma is better, especially when there is a pause before the final clause:

I failed the course, though not for lack of trying.

Your drone will get stuck in that baobab tree, when you actually get it off the ground.

So what have we learned? Stick a comma between a dependent and independent clause, but not the other way around. And, of course, both rules can occasionally be broken.

In a list

And now we come to the great controversy. When you use commas in a list, do you place one before the final item?

That final comma is called the “serial comma” or “Oxford comma,” and it’s not hard to make up sentences that show why it’s needed.

The radio host interviewed a couple of illegal immigrants, Donald Trump and Ted Cruz.

I celebrated my Bar Mitzvah with my best friends, my mom and dad.

On his trip through Italy, he met the Pope, a rabid soccer fan and an expert on opium.

My reading list includes two books on fertility, The Farmer’s Almanac and The Elements of Style.

Why do these sentences sound awkward? It’s because we might assume that the last two items in the list rename the first. In other words, they function like an appositive.

The truth is that such sentences are rare, and there is a kind of perverse joy in making them up. That said, the trend is to go with the serial or Oxford comma. The one exception is in news publications, where leaving the comma out presumably saves space and makes reading quicker.

So if you want to be safe, punctuate all your lists like this:

The serial comma is preferred by English professors, passive-aggressive types, and fussy pedants who are always rearranging their book shelves.

Around non-essential information

If information is not essential to the rest of the sentence, then you can stick it in between commas (or between a comma and a period). Here are two quick examples:

Minecraft, my brother’s obsession, bores me to death.

I was born in Sri Lanka, which was then still called Ceylon.

Here the commas act like parentheses or dashes. By contrast, when information is essential we don’t want any commas:

Sarah’s friend Tara still listens to One Direction.

We can’t place “Tara” between commas because it’s likely that Sarah has more than one friend. Her name helps to “restrict” the meaning of “friend,” and that’s why essential information is also called restrictive information (just like non-essential information is the same thing as non-restrictive information). Of course, if Sarah had just one friend, then commas would be justified.

Non-essential information can include words, phrases, and clauses. Here are some examples that will teach you some strategies for figuring out whether the information is essential or not:

Often the extra information is a participial phrase or an appositive phrase that comes right after a noun or pronoun:

Mr. Sinclair, a most respectable and bespectacled man, taught us all geography.

Everyone wearing sunglasses should vacate the building immediately.

In the second sentence, the phrase “wearing sunglasses” limits the meaning of “everyone” so that it now refers to only a specific group of people. It’s no longer “everyone,” but only those wearing sunglasses. By contrast, knowing that Mr. Sinclair is respectable and bespectacled doesn’t change the rest of the sentence.

It often happens that a detail elsewhere in the sentence makes other information non-essential. Here are some examples:

My youngest sister, Faith, dreams of playing in the WNBA.

(Since you can have only one youngest sister we don’t need her name to identify which sister is meant)

Calcutta’s saint, Mother Teresa, was born in Skopje, Macedonia.

(We don’t need Mother Teresa’s name to identify which saint is meant. Similarly, the name Skopje gives you enough information to make sense of the rest of the sentence. You could always google the name if you really wanted to know that it’s in Macedonia).

The main character, David Copperfield, is also the narrator.

(Since you can have only one main character, the name is not essential information)

Often the extra information comes in the form of a relative clause. Relative clauses start with that, which, who (and whose and whom). Here are some examples with both essential and non-essential information:

Carl Lewis, who won ten medals at the Olympics, followed a vegan diet.

The person who robbed me had a handlebar moustache and green eyes.

The rhinoceros, which may have inspired the myth of the unicorn, is often killed for its horn.

How much for that parrot that says “billions of blistering barnacles!”?

By the way, most editors prefer to use that for introducing essential information and which for inserting material that can go between commas.

Between coordinate adjectives

When you use multiple adjectives before a noun, you have to make a choice about whether to separate them with commas:

His uppity, pretentious, obnoxious mannerisms

Her bright orange bathing suit.

Why commas in the one example, but not in the other? Because in the first the adjectives all modify the noun separately. They’re called “coordinate” adjectives because you could easily substitute “and” (a coordinating conjunction) for the commas: his uppity and pretentious and obnoxious mannerisms.

This doesn’t work so well for the second example, where the adjectives work together to modify the noun. In fact, the word “bright” doesn’t modify the noun so much as the next adjective (“orange”). That’s why these adjectives are called “cumulative”—they build on each other.

The hard thing is to know whether the adjectives are coordinate or cumulative. There are two quick ways to check:

  • As mentioned, if you can put “and” between the adjectives and the phrase still sounds okay, then the adjectives are coordinate and you can insert commas between them.
  • Also, you can sometimes rearrange the order of coordinate adjectives. This is more difficult with cumulative adjectives (try say orange bright bathing suit).

However, neither of these tests is fail proof, so often you will still have to use your discretion.

Before a quotation

There are multiple ways to introduce a quotation, and one of them is with a comma. A comma is appropriate after a short signal phrase:

She asked, “Can I have another raisin bun?”

To summarize his theory of historical materialism, Karl Marx wrote, “It is not the consciousness of men that determines their being, but, on the contrary, their social being that determines their consciousness.”

The comma is particularly appropriate when the signal phrase includes a verb of expression (said, wrote, argued, suggested, etc.).

Commas: Minor Rules


In our first lesson on commas we touched on the major patterns. On this page we’ll cover the minor rules. You’ll likely be familiar with most of these, but even a quick read through may be a good refresher.

Minor Uses

There are quite a few other uses of commas. Most of these you will likely be familiar with already.

Addressing someone directly

Please, Josephine, do tell me all about your research on the habits of baboons.

Starting a letter or email

Dear Professor Jones, I hope you are doing well.

Finishing a letter or email

Sincerely, Michael Beasley.

 If some words are left out

Before we had Michael Jordan; now, Steph Curry.

After mild interjections

Oh, that’s my favourite poem by Wendell Berry.

By contrast, stronger interjections are often followed by an exclamation mark.


No, I don’t think so.

In less formal contexts you may drop the comma if it interrupts the flow (yes you may!)


When dates are included in a sentence, they are typically set off with commas:

She was born on July 14, 1789, the day the Bastille was stormed.

We will celebrate our anniversary on Tuesday, April 26, and you’re invited.

However, if the day comes before the month you don’t need a comma between them:

On 13 January 2000, Bill Gates stepped down as CEO of Microsoft.

The same rule applies if you’re only mentioning the month and the year:

The last time I saw her was in May 2015.


Addresses are usually punctuated with commas:

Please write to me at 22 Pleasant Ave, Sockville, Alberta, Canada, the World, the Universe.


There are many more minor uses, and we will likely add some over time.



Few punctuation marks are as misunderstood as the semi-colon.

A semi-colon does not just indicate a longer pause than a comma. Its main purpose is to connect independent clauses. Occasionally you can also use a semi-colon in a list.

Between independent clauses

Most of the time, a semi-colon is used to connect two independent clauses that are related in theme and content:

Buy a van if you have a family; buy a truck if you want a family.

Yesterday she upped her exercise routine; today she’s laid up in bed.

I am learning Old French; I want to read The Song of Roland in the original.

A hummingbird flashed by the window; it briefly hovered by the fuchsia and then flew away.

As these examples show, often the semi-colon is used for juxtaposition or to connect two ideas that form a whole. Sometimes you could substitute a dash, though the effect is more casual, with the result that the connection between the clauses is less clear.


  • Read each clause by itself to check if it could be its own sentence.
  • Keep your clauses relatively short.
  • Your sentence will be more balanced if the clauses have roughly the same length.
  • If you feel that the second clause is more specific and zooms in or explains the first, use a colon instead.


Use the semi-colon sparingly. Having more than one in a single paragraph can slow down your prose and may appear ostentatious. In addition, even if a semi-colon is grammatically correct, it may not be your best option. Take the following examples:

Oswald Mosely was the leader of the British Union of Fascists; in 1931, he traveled to Italy to study Mussolini’s brand of fascism.

I enjoyed listening to Michael Nyman’s score for the movie The Piano; Nyman’s compositions remind me of the piano music of Ludovico Einaudi.

In each sentence the two clauses have some bearing on each other, but they do not strictly need to be connected by a semi-colon. You could use a period instead.

Before a transitional expression

The next rule is merely a minor variation on the basic use of a semi-colon. When you connect two independent clauses with a semi-colon, you can add a transitional expression to the beginning of the second clause:

A group of librarians is called “a shush of librarians”; by contrast, a gathering of language experts is termed “a babble of linguists.”

I’m studying to become a math teacher; however, I really enjoy taking English classes.

The transitional expression is usually a conjunctive adverb.


Normally a semi-colon should not be followed by a coordinating conjunction (and, but, nor, for, or, so, yet). Avoid the following:

In 2015, more people than ever attempted to climb Mount Everest; but no one reached the summit.

In such cases a comma will do the job. Still, there is one exception. Occasionally, you can use a semi-colon before a coordinating conjunction when both clauses are quite long and involved (i.e., they contain internal punctuation):

This is a tortuous sentence, which twists and winds, and can easily confuse the reader; but a person of wit and intellect, attuned to the vagaries of language, will appreciate its clever use of a semi-colon.

If you’re not sure, just stick with a comma.

In a list with internal punctuation.

The last use of a semi-colon is quite different from the others. It is also very rare. The rule is that you are allowed to put a semi-colon between the items of a list if the items themselves already contain punctuation:

In the 1890s, Canada had four Prime-ministers in quick succession: John Abbott, who led from the senate; John Thompson, the first Catholic Prime Minister; Mackenzie Bowell, who had to deal with the Manitoba Schools Question; and Charles Tupper, a father of Confederation.

You will notice that each item in this list already has a comma (e.g., John Abbott, who led from the senate), so using semi-colons provides some clarity and organization. If there is no internal punctuation, you can use commas instead.



Colons are used to draw attention to something specific. Here are the principal uses:

1. After an independent clause and before

  • a list
  • an appositive (a noun or noun phrase that renames a nearby noun)
  • a quotation

2. Between independent clauses if the second summarizes or explains the first.

Let’s look at each of these in detail.

Before lists

A colon is often used before a list or series:

The platypus has some unusual features: the female lays eggs (despite being a mammal), the male can defend itself with a poisonous venom, and every platypus can sense electric fields.

I have only a few things on my bucket list: visiting New Zealand, learning to quilt, and having my brain transplanted to a younger body.

It’s important to check that what comes before the colon is actually an independent clause. In the following examples, no colon is needed because the initial clause is not independent, but merges with the list to form a complete sentence:

My three favourite pizza toppings are pepperoni, pineapple, and spinach.

Her playlist includes music by “The Hot Club of Cowtown,” Johann Sebastian Bach, and “Phosphorescent.”

If you want to see some great dunks, check out videos of Dr. J, Dominique Wilkins, LeBron James, or Blake Griffin.

None of these three examples requires a colon.

Before appositives

An appositive is a noun or noun phrase that renames an earlier noun phrase. You can use a colon at the end of a sentence to introduce a concluding appositive:

Why is it that artists like Jake Bugg or “The Tallest Man on Earth” imitate Bob Dylan’s worst feature: nasal singing?

You know there’s one thing I could really use this winter: a remote car-starter.

In the first example, “nasal singing” specifies what the “worst feature” is; in the second example, “a remote car-starter” clarifies what is meant by the “one thing.”

Make sure, though, that you have an independent clause before the colon. That’s why the following example is incorrect:

Incorrect: The title of his dissertation was: “In Every Orifice: The Origins of the Thermometer.”

There is no need for a colon here because the introductory clause cannot stand by itself as a complete sentence.

Before quotations

Quotations are normally preceded by a comma or a colon, if they are not simply merged with the writer’s own words. Compare the following examples:

Bernard called the accusations “preposterous.”

Stephen Leacock once quipped, “Many a man in love with a dimple makes the mistake of marrying the whole girl.”

The minister suggested the following text for our wedding: “‘I am against you,’ declares the LORD Almighty. ‘I will lift your skirts over your face. I will show the nations your nakedness and the kingdoms your shame’” (Nahum 3:5).

As the last example shows, you can put a colon before the quotation if you’ve introduced it with an independent clause.

Between independent clauses

If you want to join together two independent clauses without using a conjunction, the most common method is to use a semi-colon. However, if the second clause is more specific than the first, or if it explains what came before, then you may want to use a colon:

Swimmers and rock climbers like to know whether their arm span is longer than their body length: This measurement is called the “ape index.”

The Bogomils were Gnostic dualists: they believed that all earthly matter was evil, but that the spirit or soul was divine.

Please note that the independent clause after the colon may be capitalized (e.g., compare This and they in the examples). Whatever you choose to do, make sure you’re consistent.

Minor uses

Finally, you will have noticed that a colon is also used in time measurements, ratios, citations of biblical passages (and some other texts), and in titles:

He struggled to memorize John 11:35.

At 12:55 a.m., I finished my thesis paper, titled “Watt is Wrong With You?: Decreasing Abilities in Light Bulb Installation.”



There are two types of dashes: the em dash and the en dash. Their names come from the width of the letters M and N:

The em dash is formed with two hyphens (–) and no extra spaces, which MS Word reformats automatically to a longer dash when you keep typing.

The en dash is formed with one hyphen and no spaces around it. Again, as you keep typing, Word will lengthen the hyphen slightly to create an en dash.

Many style manuals suggest you leave no spaces around a dash (word—word). It is not unusual, though, to see instead a dash with spaces around it (word – word). Whatever usage you follow, the main thing is to be consistent.

The Em Dash

Since the em dash is the most common dash, we will just refer to it as “the dash.”  The purpose of the dash is to indicate a sudden shift in a sentence or to set off and draw attention to specific words.

Either way, the dash adds some style to your writing. Dashes make you appear nonchalant, confident, even witty. So dash off a dash—you’ll look dashing!

Let’s review the principal uses.

Before a Final Explanation

A dash is a great way to extend a sentence and add a final explanation, a list, or an appositive phrase:

In the 1986 FIFA World Cup, the quarter-final was a contest between England and Argentina—two nations that had been at war over the Falkland Islands four years earlier.

He ordered an expensive-sounding bottle of champagne—a Banlieue de Paris.

She did not want to open the envelope—it could wait.

Richard Filigree spent four months tracking the Australian elephant—the most elusive animal he had ever studied.

A flywheel is a wheel that stores and transfers rotational energy—something that is especially useful when you want to turn intermittent power into a continuous supply of energy.

Fatima’s project on the Edo culture of Japan included three demonstrations—a sumo wrestling contest, a recitation of haiku, and a dramatic demonstration of seppuku.

You’ll note that before an appositive or a list you would normally use a comma or colon. A dash simply creates a more casual effect.

After an Introductory Element

You can use a dash not only before a list, but also after one:

Tsunamis, typhoons, and tornadoes—these are a few of my favourite things.

While phoning my fiancée, arranging for a tow-truck, and writing down the registration information from the truck driver, who did not want to cooperate—while doing all these things I had no time to cry over my crumpled car.

Notice how in the second example—with its rather long list—the dash allows you to gather all your thoughts before concluding the sentence.

Around Parenthetical Information

Extra information is normally placed between commas or parentheses.  This kind of information is called “non-essential” or non-restrictive” because it does not restrict or change the meaning of the rest of the sentence—it is just extra material.

You can also place such information between dashes, though the effect is different. Dashes make the words stand out.  Here are some examples:

Until 1993—when the London Convention banned the practice—every nuclear nation simply dumped its radioactive waste into the world’s oceans.

After a brief negotiation, the union leaders—to everyone’s surprise—called off the general strike.

Alyson Twinklestar’s piano students—Esther, Emma, and Iris—were always playing pranks.

If I had my own butler—and a mansion to put him in—I would host the most wonderful parties.

As you can see from the examples, the extra material can be one or more appositives, a phrase or clause, or any other interrupting expression.

With a Break in Speech

The dash also has a rather practical function. It suggests a sudden break or shift in a speech:

“You would not dare shoot me!  You would not—”

“Do you want to marry—actually, never mind.”

“I—I apologize.”

Minor Uses

Finally, you can use a dash to indicate dialogue or in a list that uses bullet form.

Here’s how dashes can be used for dialogue:

—Have you seen his latest exhibition?
—At the gallery?
—In the park.
—No, I’m not into artists exhibiting their wares in the park.

And here’s a list that uses dashes:

This government has four main priorities:

—Raise personal income taxes
—Build more coal power plants
—Give generous severance packages to any bureaucrats with ties to the previous government
—Have more children in cabinet positions

The En Dash

As mentioned, sometimes an en dash is simply used in the place of an em dash. This is quite common in British texts.

Otherwise, the en dash has a few specific uses (though a hyphen is fine too).

The shorter en dash can be used to mean “to”:

Mahatma Gandhi (1869–1948) liked to air his dirty laundry.

The Caterpillars Rugby Club won 25–17.

The Paris–Dakar rally was first organized in 1979.

It can also connect compound adjectives, but only if they include a proper noun:

I missed my New York–Tel Aviv connection.

I love your Emily Dickinson–like obsession with dashes.

She studied post–Civil War politics.

By contrast, other compound adjectives can be connected using a hyphen.

Question Marks


You probably think you already know how to use a question mark, don’t you?

But did you know that the previous sentence ended with a “question tag,” a way to turn a statement into a question?

In other words, while question marks are fairly straight forward, there are still a few subtle points to take note of.

Asking Questions

Obviously, a question mark goes at the end of a question:

Would you visit the Karni Mata Temple, which is dedicated to the worship of rats?

However, no question mark is necessary if the question is part of a regular declarative sentence:

She asked if I would visit the Karni Mata Temple during my trip to India.

In this example, the question is implied, rather than stated directly. The sentence is merely declaring or describing that “she asked a question.” It is not actually asking the question.

This type of sentence is often called an indirect question (also called an embedded question), by which we mean that the question is part of a statement.  Here are some more examples:

My prof wanted to know if my dog also ate computers.

The dentist asked Penelope when her last checkup was.

Sometimes these statements (in which the question is embedded) can themselves become questions:

Did the dentist ask Penelope when her last checkup was?

When this happens we in fact have two questions (Did the dentist ask that? When was her last checkup?), but there is only one question mark. In other words, the second question still remains an indirect question.

These double questions can be tricky for those new to the English language.

Note for ESL Students

ESL instructors often use the term “indirect question” to describe yet another way of asking questions.

Within an ESL context, an “indirect question” is often considered a more formal and less direct way of asking a question.  It’s a way of adding words to a question to make it part of a longer sentence:

Direct question: Where is the post-office?

Indirect question: Do you know where the post-office is?

This distinction is important for ESL users because in the indirect question the word order has changed. However, the question mark still remains.

Questions in a Series

If you’re asking a number of questions in a row, each one gets its own question mark:

Mr. President, I have a few simple questions: Why did you resign? Where is the money now? What did your wife have to say?

You actually don’t even need to capitalize the follow-up questions, especially if they are short and follow a similar syntax as the original one:

Do you celebrate Women’s Day? or Peanut Butter Cookie Day? or how about Butterfly Kisses Day?

Notice too that with successive questions you can use sentence fragments for the later questions. These questions rely on the grammar of the initial sentence. However, in academic writing you may want to be more formal.

With other Punctuation

How do question marks interact with other forms of punctuation? The basic rule is that a question mark should not be combined with commas, periods, or exclamation points.

Compare the following examples, where the usual commas are dropped:

“Would you like a cup of coffee?” she said.

I asked, “Have oil prices hit rock bottom yet?” but she wouldn’t speculate.

The exception is with abbreviations, where the period remains necessary:

How long did you stay in Washington, D.C.?

In general, though, avoid piling up punctuation marks. After all, you don’t want to sound like you’re shouting at people, do you?!

Polite Requests

According to some style guides, a polite request does not need a question mark:

Could everyone please line up neatly for the bus, so that the little kids don’t get bowled over.

Will you all join me in a round of applause.

Since these requests blend into a command (they demand an action rather than a reply), a period is appropriate.

Introducing the Question

If you look through the examples above, many questions are introduced by a colon or stand by themselves as a sentence.

However, we sometimes run into awkward constructions such as the following:

The real question remains, did the Zika virus cause an increase in microcephaly cases?

His last objection was, could the defendant have finished the Rubik’s cube that quickly?

The comma here feels like hitting a bump in the road and swerving into oncoming traffic. Yet we can’t use a colon because the opening clause isn’t complete. (If you must know, remains is a transitive verb which takes an object, and that object is the question; similarly, was is a linking verb that connects the subject with the predicate nominative, i.e., the question that follows.) That’s why the comma is correct, even though it looks a bit strange.

In fact, you are even allowed to capitalize the question or invert the sentence and place the question mark in the middle:

The real question remains, Did the Zika virus cause an increase in microcephaly cases?

Could the defendant have finished the Rubik’s cube that quickly? was his last objection.

If you feel that these sentences look a bit inelegant, you can always rephrase:

He raised one last objection: could the defendant have finished the Rubik’s cube that quickly?

An important question remains: did the Zika virus cause an increase in microcephaly cases?

Why are we allowed to use a colon here? Because this time the introductory words are an independent clause. (And if you look closely, this time the verb remains is intransitive, which means that it doesn’t need a direct object.)

And that’s about it for question marks. Let’s hope you don’t have any questions.

Exclamation Marks


Exclamation Marks (also called exclamation points) are used to give emphasis to a statement and to indicate a command or an interjection:

Ouch! (interjection)

You should read my latest blog post! (emphatic statement)

I’m so happy to see you! (emphatic statement)

En garde! (command)

In each case, the exclamation mark indicates a strong feeling or emotion.

Academic usage

In academic writing, exclamation marks are exceedingly rare. The tendency is to let the words speak for themselves. Here’s an example where you might want to resist the temptation to add extra emphasis:

The ANC, the ruling party in South Africa, condemned the novel Disgrace because of its depiction of young black men raping a white woman.

Adding an exclamation mark makes the sentence seem sensationalistic, which is probably unnecessary.

With other punctuation

How do exclamation marks function in relation to other punctuation marks?

Just as with question marks, the rule is that an exclamation mark should not be combined with other punctuation. Here are some examples:

Incorrect: “Come to my party!,” she shouted.

Right: “Come to my party!” she shouted.

Incorrect: The latest opioid to hit the streets is much more powerful than fentanyl!.

Right: The latest opioid to hit the streets is much more powerful than fentanyl!

There are some exceptions. It may happen that an abbreviation precedes the exclamation mark:

I’m inspired by Martin Luther King, Jr.!

Similarly, things can get complicated when a name includes an exclamation mark:

Do you like How The Grinch Stole Christmas!?

If you find that this looks awkward you can always rephrase the sentence.

Finally, there is some dispute about whether you even need to include exclamation marks that are part of company names (e.g., Yahoo!). Some editors feel that retaining the exclamation mark is somewhat like giving the company free advertising.



Sometimes when you quote you may want to skip parts of the quotation. To show where you’ve left out words, phrases, or entire lines, you can use an ellipsis (the plural is ellipses).

An ellipsis consists of three spaced periods (. . .). Popular publications often leave out the spaces between the dots (…).

Prose Quotations

Let’s say we want to quote from the following passage from Frances Hodgson Burnett’s novel The Secret Garden (1911):

One of the new things people began to find out in the last century was that thoughts—just mere thoughts—are as powerful as electric batteries—as good for one as sunlight is, or as bad for one as poison.  To let a sad thought or a bad one get into your mind is as dangerous as letting a scarlet fever germ get into your body.

First of all, if you’re quoting just a brief snippet, you don’t have to use an ellipsis before or after:

Burnett believes that a negative mindset is “as bad for one as poison.”

In other words, we assume that the quotation is part of a longer sentence.

By comparison, if you’re skipping over a passage you will need an ellipsis:

Burnett argues that science increasingly recognized the healing powers of the mind: “One of the new things people began to find out in the last century was that thoughts . . . [are] as good for one as sunlight is, or as bad for one as poison.”

Notice that we’ve also used square brackets to make the sentence work. It used to be more common to put the ellipsis in brackets too, but that is no longer required.

Finally, here’s one more rule for prose quotations: if the ellipsis comes after a complete sentence there will actually be four dots (since the preceding sentence ends with a period):

Burnett writes, “One of the new things people began to find out in the last century was that thoughts—just mere thoughts—are as powerful as electric batteries. . . . To let a sad thought or a bad one get into your mind is as dangerous as letting a scarlet fever germ get into your body.”

You’ll notice that the period here replaces the original dash, and in general you can remove extra punctuation (commas, semi-colons, colons, dashes) around an ellipsis.

Poetry Quotations

If you’re quoting poetry, many of the same rules apply for using ellipses. Here’s an example:

In the poem “Holy Thursday,” William Blake argues that “where-e’er the sun does shine . . . Babe [infant] can never hunger there” (13, 15).

Even though we’ve left out a whole line of poetry, a single ellipsis will do the trick.

On the other hand, if you skip at least a full line in a poetry block quotation, you might indicate this by means of a full line of dots:

In “Mending Wall,” Robert Frost wonders about the point of building walls:

Something there is that doesn’t love a wall,

That sends the frozen-ground-swell under it,

And spills the upper boulders in the sun;

And makes gaps even two can pass abreast.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

No one has seen them [the gaps] made or heard them made,

But at spring mending-time we find them there. (1-4, 10-11)

As always, make sure that the ellipsis is not too intrusive. The reader should be able to make the leap from one passage to another without getting lost en route.

Interruptions and trailing thoughts

Some writers like to use an ellipsis to show a pause in someone’s speech, to suggest that a thought is unfinished, or to lend an air of mystery and drama:

“Our anniversary date is . . . what again?”

“I wish I could tell you the truth, but . . .”

And they lived happily ever after . . .

This use of the ellipsis is uncommon in academic writing, where it can come across as melodramatic.



Parentheses (singular parenthesis) are the curved brackets that you see in this sentence. You don’t want to clutter up your sentences with them (as they interrupt the flow), but they are great for adding and organizing information. Let’s review their main uses.

Main Uses

Setting aside information

Parentheses allow you to insert information and explanations that are less important:

In 1815, Napoleon Bonaparte escaped from the island of Elba (where he had been exiled the year before).

Dear Professor, my dog died (again), and so I cannot complete the assignment.

As you can see, the extra information can have a bearing on the rest of the sentence, but grammatically it’s not essential.

Often the work of parentheses can be done by commas or dashes. The difference is that parentheses do the least to emphasize the information. They tend to downplay the importance of what’s in brackets.

Adding citations

If you are using in-text citation (so not footnotes or endnotes), you’ll want to cite your sources in parentheses:

In A Spoonful of Sugar, Dr. Ginger Peppermint argues that cough medicines like HackAway and Phlegmatix “provide merely a placebo effect” (97).

Organizing lists

If you want to organize a list, you can add some helpful letters or numbers in brackets:

My honours thesis examines (1) the use of parentheses in colonial discourse, (2) the historical occlusion of minority groups within parenthetical remarks, and (3) the ironic subversion of imperial power by means of interruption and other parenthetical strategies.

Parentheses and other punctuation

Next, let’s see how parentheses interact with other punctuation marks.

Punctuation that is not part of the parenthetical remarks goes outside and after the parentheses. With exclamation points and question marks you have to decide which part of the sentence they belong to. Compare the following ways to write the same sentence, with various degrees of emphasis:

She said that her fingers were bruised from having nail extensions (as she kept bumping into things).

She said that her fingers were bruised from having nail extensions (as she kept bumping into things)!

She said that her fingers were bruised from having nail extensions (as she kept bumping into things!).

Finally, if an entire sentence is within brackets, there are two possibilities:

  • If the sentence in brackets is inserted in another sentence (this is a good example), then you don’t need to capitalize it or put a period after it.
  • (On the other hand, if the sentence in parentheses is all by itself, then you can place the period inside the brackets.)

Square Brackets


The word “brackets” can refer to either the square variety [like this] or to parentheses (like this). Some sticklers think that only square brackets deserve the name, but there’s no need to be so restrictive. Here we review the main uses of square brackets.

Inserting words in a quotation

Square brackets are used to insert extra words and explanations in a quotation:

The novel Post Captain opens with Captain Jack Aubrey looking both heroic and uncertain of his own future in the navy: “Captain Aubrey was standing by the aftermost larboard carronade [the last cannon on the left side of the ship], with a completely abstracted, non-committal look upon his face.”

The bank sent them a letter stating, “This letter verifies that the customer [me] has an account with us.”

Things get complicated when you need to change the quotation to integrate it properly. Sometimes it’s necessary to alter the capitalization of a word. Let’s say you want to quote the following passage:

“As art historians, we often miss the point that Kitsch’s paintings fetched so much money in post–World War I Germany because inflation was rampant.”

However, if you chop off the first part of the sentence, your quote will look like this:

As Edward Jones observes, “[W]e often miss the point that Kitsch’s paintings fetched so much money in post–World War I Germany because inflation was rampant.”

The reason is that if your signal phrase (your own words) ends with a comma, and the quotation is a complete sentence, the latter needs to be capitalized. You could avoid using square brackets if you change your signal phrase:

Edward Jones observes that “we often …”

This time the signal phrase and the quote form a complete sentence together, which is why capitalization is unnecessary.

Some writers go all out—changing pronouns and adding words—but square brackets should be used as little as possible. If you’re using two or more sets of brackets, there is probably a more effective way of integrating the quotation.

Pointing out an error in a quotation

Sometimes when you’re quoting a passage the author has made an error—most often a simple spelling mistake. To indicate that you’ve transcribed the quotation faithfully, and that this is not your error, you can add sic in square brackets. In Latin, sic means so or thus, and is short for sic erat scriptum (it was written thus).

In the following example, the writer points out that in the quotation the name of the yacht is written incorrectly (it should be Granma):

Daniel Martin writes, “A pivotal moment in the mythical life of Che Guevara occurred when he sailed to Cuba in the yacht Grandma [sic]” (3).

Notice that sic does not have to be in italics.

While it’s satisfying to point out an error, adding sic can seem rather pretentious, and should be kept to a minimum.

Brackets inside parentheses

If you’re using brackets inside parentheses, you can make them square:

Dear parenthesis, I am an angular square bracket with a passion for punctuation. If you share my feelings, please get in touch (my number is [587] 286-9901).

This is not a hard and fast rule though. For instance, in the sciences, some formulas that use parentheses may need to go inside square brackets. An example would be algebra equations [(a + 3) ÷ 2 = 6].