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What is a Comma Splice?

Comma Splices Explained

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Typically, when instructors tell you that you have a comma splice in your writing, what they are identifying is a single sentence that fuses two independent clauses (or two complete and separate ideas).

  • Example: Plato establishes a virtue-based system of ethics, the virtues are requisite character traits and skills.

Comma splices are problematic for two reasons. First, they make it difficult for your reader to fully comprehend the primary subject of your thought. Second, comma splices force your reader to guess at the connection you are drawing between the subjects in your sentence.

Because comma splices can cause confusion for your reader, it is advisable to revise your sentence to make your connections clear.

Four Ways to Revise a Comma Splice

Depending on the content and context of your sentence, not all of these revisions will work equally well. Try them out to see which one communicates your thoughts the best.

Method 1: Use a coordinating conjunction (or FANBOYS)

Often what is missing in the sentence is a coordinating conjunction. If you’re having trouble remembering what these are, use the mnemonic device FANBOYS: For, And, Nor, But, Or, Yet, and So. Use a coordinating conjunction to link two parallel ideas (or ideas of equal importance). And remember to use a comma before a coordinating conjunction when connecting two independent clauses.

  • Revision 1: Plato establishes a virtue-based system of ethics, and the virtues are requisite character traits and skills.

Method 2: Use a Semicolon

Use a semicolon when the logical connection between the two independent clauses is clear, but the ideas represented in each clause are closely related. A semicolon allows you to separate out your ideas within one sentence, and lets the reader know that the two clauses connect to one another in an important way.

  • Revision 2: Plato establishes a virtue-based system of ethics; the virtues are requisite character traits and skills.

Method 3: Make each clause its own sentence

Try using a period to separate the two independent clauses when the logical connection between the two is clear, and when the ideas represented in the two clauses are distinct.

  • Revision 3: Plato establishes a virtue-based system of ethics. The virtues are requisite character traits and skills.

Method 4: Consider restructuring the sentence

If one of the clauses explains or expands upon an aspect in the other clause, vary your sentence structure or switch the order of the clauses to make this connection clear to your reader. If the connection between the two clauses is unclear, restructuring is often your best bet.

  • Revision 4: Plato’s system of ethics is based on certain virtues that he identifies as requisite character traits and skills

Comma slices still a problem?

Read through your essay and identify the subject of all sentences with two or more clauses. If you have more than one subject to choose from, you may have a comma splice on your hands.


Last revised: 07/2008| Adapted for web delivery: 05/2021

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