Watch Out for Sentence Fragments & Run-On Sentences

Every sentence in formal expository writing must have an independent clause: a clause that contains a subject and a predicate. A sentence fragment has no independent clauses that are improperly connected. As you edit your practice essay, check your sentence constructions, noting any tendency toward fragments or run-on sentences.

• FRAGMENT: Global warming. That is what the scientists and journalists are worried about this month.
• CORRECT: Global warming is the cause of concern for scientists and journalists this month.

• FRAGMENT: Seattle is a wonderful place to live. Mountains, ocean, and forests, all within easy driving distance. If you can ignore the rain.
• CORRECT: Seattle is a wonderful place to live, with Mountains, ocean, and forests all within easy driving distance. However, it certainly does rain often.

• FRAGMENT: Why do I think the author's position is preposterous? Because he makes generalizations that I know are untrue.
• CORRECT: I think the author's position is preposterous because he makes generalizations that I know are untrue.

Beginning single-clause sentences with coordinate conjunctions–and, but, or, nor, and for-is acceptable in moderation (although some readers still object to beginning a sentence with and).

• CORRECT: Most people would agree that indigent patients should receive wonderful health care. But every treatment has its price.

Time pressure may also cause you to write two or more sentences as one.

When you proofread your essays, watch out for independent clauses that are not joined with any punctuation at all or are only joined with a comma.

• RUN-ON: Current insurance practices are unifier they discriminate against the people who need insurance most.

You can repair run-on sentences in any one of three ways. First, you could use a period to make separate sentences of the independent clauses.

• CORRECT: Current insurance practices are unfair. They discriminate against the people who need insurance most.

Second, you could use a semicolon. A semicolon is a weak period. It separates independent clauses are related.

• CORRECT: Current insurance practices are unfair; they discriminate against the people who need insurance most.

The third method of repairing a run-on sentence is usually the most effective. Use a conjunction to turn an independent clause into a dependent one and to make explicit how the clauses are related.

• CORRECT: Current insurance practices are unfair; because they discriminate against the people who need insurance most.

A common cause of run-on sentences is the misuse of adverbs like however, nevertheless, furthermore, likewise, and therefore.

• RUN-ON: Current insurance practices are discriminatory, furthermore they make insurance too expensive for the poor.
• CORRECT: Current insurance practices are discriminatory. Furthermore, they make insurance too expensive for the poor.