This document discusses run-on sentences and how to identify and fix them. A run-on sentence occurs when two or more independent clauses are joined incorrectly without punctuation or a conjunction. There are two main types: fused sentences which have no punctuation or conjunction between clauses, and comma splices which join clauses with only a comma. The four main ways to fix a run-on sentence are using a period, semicolon, comma with a conjunction, or subordinating conjunction.