The document discusses avoiding run-on sentences. It defines a run-on sentence as one where two clauses are connected incorrectly. Some examples of run-on sentences are provided, such as connecting two independent clauses with only a comma. Ways to fix run-on sentences are presented, such as inserting a period to separate into two sentences, using a comma plus a conjunction, or a semicolon. Situations where run-on sentences commonly occur and ways to correct them are also outlined.