Writing Correctly

Avoiding Sentence Fragments and Run-Ons

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 clause; a run-on sentence has two or more independent clauses that are improperly connected. As you edit your practice essays, check your sentence constructions, noting any tendency toward fragments or run-on sentences.

FRAGMENTS: Global warming. That is what the scientists and journalists are worried about these days.
CORRECT: Global warming is causing concern among scientists and journalists these days.

FRAGMENTS: Mountains, ocean, and forests, all within easy driving distance of Seattle, a wonderful place to live. 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 there.

FRAGMENT: Why is the author’s position preposterous? Because he makes generalizations that go beyond the facts.
CORRECT: The author’s position is preposterous because he makes generalizations that go beyond the facts.

Beginning sentences with coordinating conjunctions—for, and, nor, but, or, yet, and so—is acceptable in moderation and is sometimes an effective stylistic choice to emphasize an idea. Nonetheless, check whether joining sentences with the conjunction or using an adverb, such as moreover or however, would be more effective.

CORRECT: Most people would agree that indigent patients should receive excellent health care. But every treatment has a price.
CORRECT: Most people would agree that indigent patients should receive excellent health care. However, every treatment has a price.

Time pressure may cause you to write two or more sentences as one. When you proofread your essays, watch out for independent clauses that are not joined properly.

RUN-ON: Current insurance practices are unfair 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.

You could also use a semicolon. A semicolon functions like a weak period; it separates independent clauses but signals to the reader that the ideas in the clauses are related.

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

Yet another method of connecting clauses is to use a conjunction, which makes explicit how the clauses are related. If you use one of the FANBOYS (For, And, Nor, But, Or, Yet, So) coordinating conjunctions to connect independent clauses, you must also insert a comma before the conjunction.

CORRECT: Current insurance practices are unfair because they discriminate against the people who need insurance most.
CORRECT: Current insurance practices are unfair, for 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. These words may not be used to connect clauses.

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.

Avoiding Sentence Fragments and Run-ons Practice Set

Read the sentences below and make revisions to correct fragments and run-ons.

The writer of this letter lays out an incoherent argument about why Adams Realty is superior it is disorganized, has weak points and with unclear examples, and so is unconvincing.
Leadership ability. That is the elusive quality that our current government employees have yet to capture.