A modifier is simply a descriptive part of a sentence (basically anything that acts like an adverb or an adjective). You want the modifier to be close to what it describes.
This is how not to do it:
Comedian Quentin Blakely visited our local pub, the one with the pink bathroom, where he performed quite a number.
You can see that the last clause should come right after the word pub, which is what it is meant to describe. If you see no easy way to fit in the other bit (the one with the pink bathroom) then use two separate sentences instead.
Let’s review the most common causes of misplaced modifiers. Don’t let the range of examples confuse you. In fact, the problem is always the same: some descriptive words are in the wrong place.
You may recall that prepositional phrases act like an adverb or an adjective. It’s important, then, to avoid mistakes like this:
I heard the news about the President’s assassination in my bed.
Correct: While I was still in bed, I heard the news about the President’s assassination.
Other phrases can be misplaced as well. Here’s an example of a participial phrase that’s out of place:
We saw many paintings walking through the Louvre.
Correct: Walking through the Louvre, we saw many paintings.
Sometimes there’s too much of a delay between the subject and the main verb:
Our Christmas cactus, which produces the most amazing pink flowers and gives us all joy during the long winter, is in bloom again.
Correct: Our Christmas cactus is in bloom again. It produces the most amazing pink flowers and gives us all joy during the long winter.
The previous example also shows the problems that relative clauses can create. A relative clause starts with a relative pronoun (who, whom, which, that, whose) or a relative adverb (when, where, why). Here is an example of a misplaced relative clause:
Tim and Irene hired a name consultant to research the name for their baby that they had in mind.
Correct: Tim and Irene hired a name consultant to research the name that they had in mind for their baby.
Since appositives also interrupt the flow of the sentence, they too can mess up your syntax:
I did a road trip with Frank Ostrogoth, an expert on Julius Caesar, who drove his Jeep Wrangler Rubicon.
Correct: I did a road trip with Frank Ostrogoth, an expert on Julius Caesar. Frank drove his Jeep Wrangler Rubicon.
Some adverbs are frequently placed too early in the sentence. The main culprit is only:
In my entire life, I’ve only slept in once or twice.
Correct: In my entire life, I’ve slept in only once or twice.
At first glance it may be hard to see what’s wrong. However, the incorrect sentence implies that the speaker has done very little in his or her life. He has done a bit of sleeping in, and that’s all.
Here’s another case of a misplaced adverb:
With my last lottery ticket I almost won a million dollars!
Correct: With my last lottery ticket I won almost a million dollars!
From a financial perspective, there is quite a difference between the two versions.
Finally, if you’re using a common expression, don’t insert other words in the middle:
Please don’t put words that I never even said in my mouth.
Correct: Please don’t put words in my mouth that I never even said.
Finish the expression (putting words in my mouth) before you move on. If you find the result awkward, then rewrite some more.
And that’s in fact what you should do with any misplaced modifier. There’s no easy fix. Rearrange the syntax or add another sentence to convey your ideas clearly.