The document discusses sentence fragments and how to identify and repair them. It defines a complete sentence as having a subject, verb, and expressing a complete thought. Fragments are incomplete sentences that are missing one or more of these elements. They can be repaired by either attaching the fragment to a nearby complete sentence, or by adding missing words to make the fragment standalone. The document provides examples of fragments and how to identify them based on whether they contain a verb or subject. It also gives examples of how to repair fragments using attachment or addition.