Resources for Sentence Errors: Comma Splices, Run-ons, and Fragments

Rules for Comma Splices

A comma splice is the unjustifiable use of only a comma to combine two separate sentences. (One should use either a period, a semicolon, or a coordinating conjunction and a comma to separate the two statements.)

Comma splice:  Wearing a seatbelt is not just a good idea, it's the law.

Revision:  Wearing a seatbelt is not just a good idea; it's the law.

Both run-on sentences and comma splices may be corrected in any of the following ways:

Run-on:  Tevon won the award he had the highest score.

Comma splice:  Tevon won the award, he had the highest score.

 

1.  Separate the sentences with a period.

Example:  Tevon won the award. He had the highest score.

2.  Separate the sentences with a comma and a coordinating conjunction (for, and, nor, but, or, yet, so).

Example: Tevon won the award, for he had the highest score.

3.  Separate the sentences with a semicolon.

Example: Tevon won the award; he had the highest score.

NOTE: If a conjunctive adverb like therefore, however, then, or consequently separates the two sentences, use a semicolon also.

Example: I was unwilling to testify; however, I did it anyway.

4.  Separate the sentences with a subordinating conjunction such as although, because, since, or if.

Example: Tevon won the award because he had the highest score.

Rules for Run-ons

A run-on or fused sentence is two independent clauses that are not separated by any punctuation.

Run-on:  Wearing a seatbelt is not just a good idea it's the law.
Revision:  Wearing a seatbelt is not just a good idea; it's the law.

NOTE:  Even if one or both of the fused sentences contain internal punctuation, the sentence is still a run-on.

Rules for Sentence Fragments

A fragment is an incomplete construction which may or may not have a subject and a verb. Specifically, a fragment is a group of words pretending to be a sentence.

Fragment:  Traffic was stalled for ten miles on the freeway. Because repairs were being made on potholes.
Revision:  Traffic was stalled for ten miles on the freeway because repairs were being made on potholes.

Fragment:  It was an excellent movie; one that was nominated for an Oscar.
Fragment:  It was an excellent movie. One that was nominated for an Oscar.
Revision:  It was an excellent movie, one that was nominated for an Oscar.

Fragment:  Prospectors invaded the newly discovered territory. Some in wagons, some on horseback, and a few in heavily laden canoes.
Fragment:  Prospectors invaded the newly discovered territory; some in wagons, some on horseback, and a few in heavily laden canoes.
Revision:  Prospectors invaded the newly discovered territory, some in wagons, some on horseback, and a few in heavily laden canoes.