Run-ons occur when two complete thoughts are joined without proper punctuation or conjunction. There are two main types: fused sentences which have no punctuation between thoughts, and comma splices which incorrectly use only a comma. To correct run-ons, one can use a period and capital letter to separate thoughts, a comma with a conjunction, a semicolon alone or with a transition word, or subordinate one thought. Reading sentences aloud can help identify run-ons.