The document discusses subject-verb agreement rules. It covers how singular and plural subjects take singular or plural verbs respectively. It provides examples of how subject-verb agreement works in sentences with phrases, clauses, indefinite pronouns, compound subjects, contractions, collective nouns, predicate nominatives, inverted word order, amounts, exceptions, titles, subjects preceded by every or many a, and clauses within sentences. The document aims to clearly explain the rules around matching subjects and verbs.