Phrases that do not clearly and logically refer to a noun or pronoun are called dangling modifiers. Dangling modifiers usually appear at the beginning of a sentence.
To test whether a phrase is a dangling modifier, turn it into a clause with a subject and a verb in the same voice (active or passive) as the independent-clause verb. If the expanded phrase and the independent clause do not have the same subject, the phrase is dangling.
After finishing lire research, the paper was easy to write.
In this example, the implied subject of the phrase is I ("After I finished the research"), and the subject of the independent clause is paper. Therefore, the modifier is dangling, and the sentence should be recast.
To revise a dangling modifier, change the subject of the independent clause.