Handout Topic: Comma Splices   
What is a comma splice?

A comma splice is an error of punctuation, and is caused by joining two independent clauses with a comma. Independent clauses are clauses that do not require any other words or punctuation: they can stand alone as grammatically correct sentences. Single commas that appear in the middle of a sentence and seem to divide the sentence into two generally equal parts should be checked carefully.

e.g. Jenn wrote the handout for MLA style, it should be helpful for students in the arts. (comma splice: comma is joining two independent clauses together)

There are three main ways to correct a comma splice such as the one in the example above.

1) Replace the comma with a semicolon.
e.g. Jenn wrote the handout for MLA style; it should be helpful for students in the arts.

2)  Replace the comma with a period and create two sentences.
e.g. Jenn wrote the handout for MLA style. It should be helpful for students in the arts.

3) Add an appropriate coordinating conjunction (e.g. and, but, so, for, yet) immediately following the comma.
e.g. Jenn wrote the handout for MLA style, and it should be helpful for students in the arts.

Although all three methods are equally acceptable, too many short sentences can result in choppy writing. In other words, if two thoughts are closely related enough to appear in the same sentence (joined either by a coordinating conjunction or a semicolon), then the last two methods above are preferable.          

N.B. When used in the middle of sentence to signal a strong shift (rather than to make a parenthetical comment), conjunctive adverbs (e.g. however, therefore, nevertheless, thus) can easily create comma splices.

e.g. The assignment is due tomorrow, however I received an extension until Monday. (incorrect: comma splice)
e.g. The assignment is due tomorrow; however, I received an extension until Monday. (correct)         

Exercises: Determine which of the following sentences contain comma splices, and fix them appropriately. (Some examples may be correct as they appear.)

1. Most of my friends are going to the concert, unfortunately, I won’t be able to.

2. Sandra licked the stamp, mailed the letter, and then returned home, feeling like she had accomplished something important.

3. Far too many accidents are preventable, said the police officer, I couldn’t agree more.

4. They expected the lecture to be boring, they found it, however, extremely informative and even entertaining.

5. The baseball season has just started, the hockey season is almost over.