We call dependent clauses that aren't clearly connected to independent (or main) clauses dangling modifiers.
Dangling modifiers are often hard to recognize in your own and others' work. See if you can pinpoint the problem in the following sentences:
In each sentence above, the introductory phrase (the dependent clause) modifies a subject not clearly stated in the sentence. More specifically, the implied subject in each phrase differs from the subject of the main clause. For example, the implied subject of "After killing two victims," is the murderer, but it's the police who appear as the subject of the main clause, a mismatch that suggests the police killed two victims and then arrested the murderer. Click here for more on dependent and independent clauses.
As you'd expect, confusion is inevitable on this point because you can often omit the subject of a dependent clause (identified in red below) if it is the same as the subject of the independent clause. For example:
In Example 5, the subject of both the dependent and the independent clause is "John." In Example 6, however, the subject of the dependent clause (i.e., "John") is not the same as that of the independent clause (i.e., "Mary"), and so both subjects are necessary. If one were to omit the subject from the first clause, the result would be: "After taking the exam, Mary invited him to dinner." This change would suggest that Mary is the person who took the exam and confuse what we know is the intended meaning of the sentence.
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