Beware of two common sentence-writing errors:

  • Sentence fragment: a statement with no independent clause
  • Run-on sentence: two or more independent clauses that are improperly connected

1. Sentence Fragments

Every sentence in formal writing must have an independent clause: a clause that expresses a complete thought and can stand alone. Dependent clauses do not express a complete thought and cannot stand alone.

(a) Independent Clause: Brian must study for many hours.

(b) Dependent Clause: since school is so difficult.

Clause (a) is an independent clause because it expresses a full thought, which is a complete sentence.

Clause (b) is not a complete thought. It contains the subordinate conjunction “since,” making it unfinished. It needs an independent clause to make a full sentence:

Brian must study for hours since school is so difficult.

Errors are made when a dependent clause is used without an independent one.

Independent clauses contain a subject and a predicate and do not begin with a subordinate conjunction such as:

 after as while
 if provided that before
 so that though where
 whenever whether than
 although because unless
 in order since that

NOTE: Beginning single-clause sentences with coordinate conjunctions such as andbutornor, for is acceptable in moderation, although some readers may object to beginning a sentence with And.

2. Exercise: Fragments

Rewrite each example as complete sentences.

1. Global warming. That is what the scientists and journalists are worried about this month.

ANSWER

Global warming is the cause of concern for scientists and journalists this month.

2. Seattle is a wonderful place to live. Having mountains, ocean, and forests all within easy driving distance. If you can ignore the rain.

ANSWER

Seattle is a wonderful place to live, with mountains, ocean, and forests all within easy driving distance. However, it certainly does rain often.

3. Why do I think the author’s position is preposterous? Because he makes generalizations that I know are untrue.

ANSWER

The author’s position is preposterous because he makes generalizations that I know are untrue.

3. Run-on Sentences

Run-on sentences occur when two or more sentences are written as one. Time pressure may cause you to write run-ons. When you proofread your essays, watch out for independent clauses that are not joined with any punctuation or are only joined with a comma.

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

You can repair run-on sentences in two ways:

1. Use a period to make separate sentences of the independent clauses.

2. Use a conjunction to turn an independent clause into a dependent one and to make explicit how the clauses are related. (This method is usually the more effective.)

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

One cause of run-on sentences is the misuse of adverbs, such as however, nevertheless, furthermore, likewise, and therefore.

4. Exercise: Run-on Sentences

Rewrite the following examples, eliminating any run-on sentences.

1. Current insurance practices are discriminatory, furthermore they make insurance too expensive for the poor.

ANSWER

Current insurance practices are discriminatory. Furthermore, they make insurance too expensive for the poor.

2. However much she tries to act like a Southern belle, she cannot hide her roots, she will always be the daughter of a Yankee fisherman.

ANSWER

However much she tries to act like a Southern belle, she cannot hide her roots. She will always be the daughter of a Yankee fisherman.

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