Two of the most common punctuation mistakes in student writing are the run-on sentence and the comma splice.

Run-On Sentences

A run-on sentence occurs when two or more independent clauses are connected in a sentence without the proper punctuation. Here is an example of a run-on sentence:

Incorrect:

  • Paul had to stay up all night to finish the project he had put it off for weeks.

This is a run-on sentence because there are two complete, independent clauses but no punctuation. Therefore, we must add punctuation and/or change the sentence by adding or removing words:

Corrected:

  • Paul had to stay up all night to finish the project; he had put it off for weeks.

Other options:

  • Paul had to stay up all night to finish the project because he had put it off for weeks.
  • Paul had to stay up all night to finish the project that he had been putting off for weeks.

Comma Splices


Unlock full access by logging in. Registered users can explore the entire lesson and more.

keyboard_arrow_up