A modifier is a word or phrase that qualifies another word or phrase. In English, separating a modifier too far from the word or phrase it modifies can confuse or mislead your reader. In reading a sentence with an introductory modifying phrase, our natural tendency is to apply the modifier to the first noun or noun phrase that follows. Consequently, if the noun or noun phrase following the modifier is not the one modified, or if no noun or noun phrase follows, the result will seem odd and will possibly create uncertainty. In such sentences, the modifier is said to be dangling. In the examples below, the dangling modifiers are italicized, and the modified nouns are in boldface:
- Driving to Philadelphia, the sun got in her eyes.
- Bewitched, bothered, and bewildered, love had struck again.
- Approaching the 490 exit, traffic slowed down.
Since - to repeat - we naturally construe the first noun following an introductory modifier to be the modified noun, the first two sentences seem to advance absurd propositions: one, that the sun was driving to Philadelphia, and the other, that love itself (rather than the person struck by it) was bewitched, bothered, and bewildered. The third sentence doesn't sound odd at all. The question is, does it say what the author meant? If the author meant that traffic approaching the exit slowed down, while other traffic in the same direction proceeded smoothly, then the sentence is unproblematic. But if the author - let's call her Jane - meant that as she approached the exit, she found that all traffic had slowed, then Jane needs to get herself into the sentence in the place currently occupied by the traffic. Here are suggested revisions for the three sentences:
Driving to Philadelphia, the sun got in her eyes.
Driving to Philadelphia, she had the sun in her eyes.
Bewitched, bothered, and bewildered, love had struck again.
Bewitched, bothered, and bewildered, he had been struck by love again.
Approaching the 490 exit, traffic slowed down.
Approaching the 490 exit, I saw that traffic had slowed down.
A dangling modifier is one variety of misplaced modifier. That modifier placement affects meaning is illustrated by the following sentences:
- The Provost only summoned the professor. (I.e., the Provost summoned but did nothing else.)
- The Provost summoned only the professor. (I.e., the Provost summoned the professor and no one else.)
- Only the Provost summoned the professor. (I.e., the Provost and no one else summoned the professor.)
In spoken English, (1) might very well be used to convey the meaning assigned here to (2). The speaker's intonation and pacing, in conjunction with the context, would probably prevent misunderstanding. Writing, however, calls for greater precision. Although usage experts are divided over whether it's acceptable to use (1) to mean (2) in written prose - with some expressing confidence that there, too context will ensure understanding - we recommend that, in general, you do everything in your power to erase doubt.