This document discusses subject-verb agreement in English grammar. It explains that the verb must match the subject in number, with singular verbs used for singular subjects and plural verbs for plural subjects. Some tricky cases are covered, such as compound subjects, collective nouns like "everybody", prepositional phrases, and questions. The key is to identify the subject and check that it agrees with the verb in number. Mastering subject-verb agreement is important for constructing grammatically correct sentences.