Avoiding Run-Ons and Comma Splices

A run-on sentence incorrectly runs together two independent clauses (two complete sentences) without a conjunction (and, or, but) or punctuation. This error confuses the reader, who cannot tell where one thought stops and the next begins:

• My neighbor Mr. Hoffman is seventy-five years old he plays tennis every Saturday afternoon.

A comma splice incorrectly joins two independent clauses with a comma but no conjunction:

• My neighbor Mr. Hoffman is seventy-five years old, he plays tennis every Saturday afternoon.

The run-on and the comma splice can be corrected in five ways:

1. Use two separate sentences:

• My neighbor Mr. Hoffman is seventy-five years old. He plays tennis every Saturday afternoon.

2. Use a coordinating conjunction:

• My neighbor Mr. Hoffman is seventy-five years old, but he plays tennis every Saturday afternoon.

3. Use a subordinating conjunction:

• Although my neighbor Mr. Hoffman is seventy-five years old, he plays tennis every Saturday afternoon.

4. Use a semicolon:

• My neighbor Mr. Hoffman is seventy-five years old; he plays tennis every Saturday afternoon.

5. Use a semicolon and a conjunction:

• My neighbor Mr. Hoffman is seventy-five years old; however, he plays tennis every Saturday afternoon.

Avoiding Sentence Fragments

Another error to avoid is the sentence fragment. A sentence must contain a subject and a verb and must be able to stand alone as a complete idea. A sentence fragment, therefore, can be defined in terms of what its lacks: either a subject or a verb, or both -- it cannot stand alone as a complete idea. Here are some common kinds of sentence fragments and ways to correct them:

1. Complete sentence: Kirk decided to major in psychology.

2. Fragment: Since human behavior had always fascinated him.

Example 1 is a complete sentence. Example 2 is a fragment because it is a dependent clause beginning with the subordinating conjunction since. Furthermore, it is not a complete idea. This fragment can be corrected in two ways:

• Corrected: Kirk decided to major in psychology since human behavior had always fascinated him.

• Corrected: Kirk decided to major in psychology. Human behavior had always fascinated him.

In the first corrected sentence, the fragment is combined with the sentence before it. In the second corrected sentence, the fragment is changed into a complete sentence.

3. Fragment: A fine pianist.

4. Complete Sentence: Marsha won a scholarship to Juilliard.

Example 3 is a fragment because it lacks a verb and is not a complete idea. Example 4 is a complete sentence. This fragment can be corrected in two ways:

• Corrected: A fine pianist, Marsha won a scholarship to Juilliard.

• Corrected: Marsha won a scholarship to Juilliard. She is a fine pianist.

In the third corrected sentence, the fragment is combined with the sentence after it. In the fourth corrected sentence, the fragment is changed into a complete sentence by the addition of a verb, is, and a subject, she.

5. Complete sentence: Daniel can always be seen on the track in the morning.

6. Fragment: Running a mile or two before breakfast.

Example 5 is a complete sentence. Example 6 is a fragment because it lacks a subject and because an -ing verb cannot stand alone without a helping verb. This fragment can be corrected in two ways:

• Corrected: Daniel can be seen on the track in the morning, running a mile or two before breakfast.

• Corrected: Daniel can always be seen on the track in the morning. He runs a mile or two before breakfast.

In the fifth corrected sentence, the fragment is combined with the sentence before it. In the sixth corrected sentence, the fragment is changed into a complete sentence.