Fragments are incomplete sentences. To be a complete sentence, a word group must contain at least one main (independent) clause; that is, it must have both a subject and a complete verb (not a participle form of the verb by itself), and it must not be a dependent clause all by itself (must be attached to an independent clause). Intentional fragments are permissible in some cases, such as in creative writing (stories, novels) and informal writing (personal letters and essays). Fragments should be avoided in most formal and academic writing situations.
You can fix fragments in two ways. First, you can add the missing elements to the sentence. Second, you can attach the fragment to a nearby sentence, but only if this makes sense. To check for a fragment, look at the sentence to see if it contains any of the following:
Several types of fragments commonly occur in writing:
1. A group of words without a subject and/or a verb. Sentences need both subjects and verbs.
2. An -ing verb without a form of the verb “be” (a helping verb). These are known as participial phrases. Without a form of the verb “be” these word groups become fragments.
3. Dependent clause not attached with an independent clause. Look for word groups beginning with a subordinating word, e.g., although, because, if, when, while; or with a relative pronoun, e.g., who, whom, which, that. This type of clause must be attached to an independent clause.
4. Phrases beginning with prepositions (after, during, in, on, instead of). Prepositional phrases need to be connected to independent clauses. Alone, they are fragments.