Italics add emphasis to a word or phrase. They are also used for certain titles.
In the past, underlining was often used instead of italics. However, these days italics are preferred. The only time underlining still comes in handy is if you’re writing by hand (say on an exam). In that case, underlining is clearer than italics.
Titles of longer, independent works are italicized, whereas titles of shorter works are placed between quotation marks.
The following list provides some examples of each:
As you can see, the shorter works are often included in the longer ones (e.g., a song is part of a cd).
If a newspaper or journal title starts with “the,” you don’t have to italicize and capitalize it:
Do you subscribe to the Wall Street Journal?
Watch out for place names that are not actually part of the title. These should not be in italics:
the London Times
On the other hand, titles that include the place name should be entirely in italics:
the Sydney Morning Herald
Do not use italics or quotation marks for the Bible and the Qur’an (other acceptable spellings are Koran and Quran).
The same goes for their individual books and suras (when named and not numbered):
John 3:16 may well be the most famous verse in the Bible.
Note, however, that specific editions of the Bible are italicized:
New International Version
King James Bible
Be careful to distinguish between punctuation that is part of the title (and should be in italics) and punctuation that is part of the rest of the sentence:
We read Horton Hears a Who! And The Cat in the Hat.
The exclamation mark is part of the title whereas the period is not.
Use italics for the name of any kind of transportation device or vehicle.
Admiral Graf Spee (ship)
Enola Gay (airplane)
Voyager I (space probe)
Orient Express (train)
Lightning McQueen (car)
By contrast, names of brands (e.g., Toyota) are not italicized.
If you draw attention to a particular word or phrase you can put it in italics:
My favourite word is serendipity, followed closely by propinquity.
In tech babble, the term unicorn refers to a start-up venture that has been valued over 1 billion dollars.
You can also use quotation marks around such words—the main thing is to be consistent.
In addition to words, you can also draw attention to letters and numbers:
I always forget the second c in the word occasion.
He says the number 0 in his password symbolizes ignorance.
It’s less necessary to use italics when drawing attention to numbers, since they naturally stand out from the text.
You can use italics to add some emphasis. This is useful in dialogue, where you may want to capture what word was stressed by a speaker:
I did tell you!
However, most editors prefer to minimize the use of italics for this purpose. This is especially the case in academic writing.
If you use a word or phrase from a different language, you should write it in italics.
He is such a shlimazel!
However, if you feel that the phrase has become part of the English language and will be readily understood then there’s no need for italics:
Don’t make a faux pas by eating too many hors d’oeuvres.
Obviously this is a judgment call. You will need to know both the language and your audience.