Sentence Structure and Commonly Confused Words

Clauses and Sentence Fragments

A complete sentence must contain at least one independent clause with a subject and a predicate. An independent clause expresses a complete thought and can stand alone as a sentence. In contrast, a dependent clause contains a subject and a verb but cannot stand alone as a complete sentence. When a dependent clause is punctuated with a period as a standalone sentence, it constitutes a sentence fragment.

A sentence fragment is an incomplete sentence that lacks a subject, a verb, or a complete thought. Fragments frequently occur when a writer punctuates a dependent grammatical unit as if it were an independent clause. For instance, a prepositional phrase standing alone without an independent clause constitutes a sentence fragment. Likewise, a participial phrase standing alone without a main clause constitutes a sentence fragment.

Not all sentences with an unstated subject are fragments. An imperative sentence expresses a command and possesses an understood subject of 'you.' Because this understood subject is recognized in English grammar, an imperative sentence like 'Wait here' is grammatically complete despite the subject being omitted.

Writers can repair sentence fragments using two primary approaches. A sentence fragment can be corrected by connecting it to an adjacent independent clause. Alternatively, some sentence fragments can be corrected by adding a missing subject or finite verb to establish a complete thought.