A fragment is either an incomplete sentence, lacking a complete subject or predicate, or a dependent clause punctuated incorrectly as a sentence.
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Because a fragment can often be edited in several ways, begin by considering what the fragment lacks and how its ideas relate to those in the sentences before and after it. Then use one of the following strategies to change the fragment into a complete sentence.
Connect the fragment to a complete sentence.
To edit the fragment in the opening example, the writer might connect it to the preceding sentence.
Eliminate the subordinating word(s) that make a clause dependent.
Add or complete the verb or subject to change a fragment into a complete sentence.
Exception: Use fragments intentionally for emphasis or special effect.
Use intentional fragments cautiously. Especially in academic writing, readers may perceive them as errors, regardless of your intentions. In the preceding example, the same impact might also be achieved by using a colon or dash.