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Grammar resource: Comma splices

“The use of the comma to 'splice' two sentences is generally unacceptable and considered a particular fault in student writing.”

Christine Sinclair, Grammar: A Friendly Approach

What is a comma splice?

To avoid run-ons, some students punctuate the two ideas by adding a comma – but this is incorrect and creates a special kind of run-on called a comma splice. This is where two independent clauses (separate ideas that could theoretically stand alone as two sentences) are joined by a comma instead.

Here are some examples:

The experiment was unsuccessful, the temperature was not controlled sufficiently.

The opening paragraph was incredibly moving, it touches on the common fear of losing a loved one.

Money is not the only motivating factor for people to work, self-worth and the need for more social interaction can also be reasons for working.

Video

Correcting comma splices

There are three ways to correct comma splices:

  1. Replace the comma with a conjunction:
    The experiment was unsuccessful because the temperature was not controlled sufficiently.
  2. Replace the comma with a semi-colon:
    The opening paragraph was incredibly moving; it touches on the common fear of losing a loved one.
  3. Replace the comma with a full stop:
    Money is not the only motivating factor for people to work. Self-worth and the need for more social interaction can also be reasons for working.

The method you choose will depend on your particular sentence and how closely you want the two clauses to be associated.