Subordinate clauses contain subjects and verbs, so they are easily mistaken for sentences. But they also contain a signal — a subordinating conjunction or a relative pronoun — that they aren’t intended to be fully understood on their own. They depend on a main clause for some of their meaning.

Because, a subordinating conjunction, makes sense only if it’s understood in relation to the previous sentence. It turns the second word group into a fragment. One way to correct the fragment is to connect the subordinate clause to the previous sentence.

In the example above, a comma between the clauses indicates that the information in the subordinate clause is not essential to the main point of the sentence (see p. 695).

Another way to correct fragments is to delete or change the wording that requires them to connect to another clause:

Dinner is served at five sharp. The kitchen workers go off duty at six.

Vogon Soup has two alpha males. They are the lead guitarist and the drummer.