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Home » Module 1 Unit 2: Run on sentences » Common mistakes - page 1/5
Unit 1: Sentence fragmentsUnit 2: Run-on sentences Unit 3: Subject-verb agreementUnit 4: TensesUnit 5: PassiveUnit 6: ApostrophesUnit 7: Articles

Common mistakes

This section analyses some common problems with run-on sentences and how to fix them.

Have you got a piece of your own writing handy? Check it to see if you are making any of these common mistakes.

Mistake 1 - You use a comma by itself to join two simple sentences.

Look at the two simple sentences below and think about how you would join them.

1. Behaviourist approaches were widely used at this time to modify the behaviour of wayward children.

2. These approaches were not very successful.

Which of these sentences joins the two sentences correctly?

Students sometimes think that, because the information in the second sentence clearly relates to the information in the first sentence, a comma will do to join them. In the example above, these approaches (Sentence 2) clearly relates to behaviourist approaches (Sentence 1). This is not a reason to join the sentences using a comma only. You must use a co-ordinating or subordinating conjunction OR leave them as two separate sentences.