This document discusses run-on sentences and comma splices. It defines run-on sentences as sentences made up of two complete thoughts with no clear break between them. There are two types of run-on sentences: fused sentences and comma splices. Fused sentences simply stick two complete thoughts together with no punctuation, while comma splices incorrectly use only a comma to join two complete thoughts. The document provides examples and guidelines for identifying and correcting run-on sentences and comma splices.