A modifier is a word or phrase that changes the nature of the information in a sentence without altering the sentence’s grammatical structure by its inclusion or omission.
The specific varieties of modifier misuse follow.
1. Dangling modifier
A dangling modifier is one in which the introduced word or phrase seems to be associated with the subject rather than the object, or with nothing. In “A keen observer of popular culture, Smith’s words are as pertinent as they are poetic,” Smith’s words, rather than Smith himself, are said to be a keen observer.
To unambiguously make the intended point, the writer should form the “keen observer” comment as a complete clause and conclude the sentence with a separate clause: “Smith is a keen observer of popular culture, and his words are as pertinent as they are poetic.”
2. Dangling participle
This sentence errs by not explicitly mentioning the object—in this case a person preceding others as they follow a path that leads to a clearing—and thereby suggesting that the path, rather than a person, led the way.