The document discusses different types of sentence errors: run-on sentences, fragments, and provides examples and explanations of each. There are three main types of run-on sentences discussed: fused sentences connected with just a coordinating conjunction, sentences run together without any punctuation, and sentences run together with just a comma. The document also discusses the three types of fragments: phrases, dependent clauses, and a combination. It provides examples of each and explains the different ways to correct fragments, such as adding an independent clause or changing a dependent clause to independent.