An incomplete sentence (or sentence fragment) is a group of words that has been written as if it were a complete sentence, but that, as a matter of grammatical correctness, needs something else to make it complete. If you write “And in the morning” and put a period after what you have written, the sentence has been left incomplete. It’s a sentence fragment, not a complete sentence. Your reader will be left wondering “And in the morning, what?” Similarly, the group of words “When the meeting ends” cannot form a complete sentence on its own; grammatically, it is structured as a dependent (or subordinate) clause. Like independent clauses, dependent clauses—also known as “subordinate clauses”—include both a subject and a verb. Unlike independent clauses, though, they begin with a subordinating word (words such as because, so, although, and when may be used as conjunctions in this way, as can relative pronouns such as that, which, and whose). To turn a subordinate clause into a complete sentence, one can either transform it into an independent clause (“The meeting will end tomorrow”) or attach it to a separate, independent clause (“When the meeting ends tomorrow, we should have a comprehensive agreement”).
Focusing on the word “fragment,” some people imagine incomplete sentences to be always very short. That’s not the case. Whether a sentence is complete or not is a matter of grammatical correctness, not of sentence length. For example, the short group of words “Marina walked to the sea” can form a complete sentence, but this much longer group of words is a sentence fragment: “While Marina was walking to the sea and thinking of her father and the sound of a woodthrush.”
More on sentence fragments and run-on sentences may be found in The Broadview Guide to Writing under “Punctuation: The Period,” and in The Broadview Pocket Guide to Writing under “Incomplete Sentences” and “Run-On Sentences.” If you are unclear on the meanings of subject and predicate, clause and phrase, or main clause and subordinate clause, see “Parts of Sentences” in “Basic Grammar: An Outline” (included in both the full Broadview Guide to Writing and The Broadview Pocket Guide to Writing).
Analyze and identify the sentence status of each of the following examples (all of which have been adapted from student papers).