Sentence fragment

A complete sentence needs three things: a subject, a verb, and a thought that can stand alone. Remove any one of them and you have a fragment. "Ran across the field" has a verb but no subject. "The tall runner in the blue jersey" has a subject but no verb. "Because the train was late" has both a subject and a verb, but the word because makes it a dependent clause that leaves the reader waiting for the rest.

Fragments usually appear in three forms. Dependent clause fragments begin with a subordinating conjunction such as because, although, when, since, or if. Phrase fragments are prepositional, appositive, or participial phrases cut loose from the sentence they belong to, as in "Running toward the exit." Missing-verb fragments often result from mistaking a participle for a main verb — "The committee meeting in the auditorium" needs was to become a sentence.

There are two reliable fixes. Attach the fragment to the adjacent independent clause, usually with a comma: "Because the train was late, we missed the opening." Or supply whatever the fragment lacks so it stands alone: "The train was late." Writers occasionally use fragments deliberately for emphasis in fiction and advertising, but standardized tests treat them as errors without exception.

The ACT English section tests fragments heavily in its sentence structure questions. You will see an underlined portion where a subordinating conjunction or a participle has turned an otherwise complete sentence into a fragment, and the correct answer either joins it to a neighboring clause or restores the main verb. Reading the underlined portion by itself and asking whether it could stand alone is the fastest way to spot one.