This document discusses subject-verb agreement and the rules for matching verbs with singular and plural subjects. It notes that singular subjects require singular verbs, while plural subjects require plural verbs. Examples are provided showing how verbs change from their singular to plural forms depending on whether the subject is singular or plural. The document also discusses how group nouns can be either singular or plural depending on whether the group is viewed as a whole or as individuals. Finally, it addresses some nouns that end in "s" but are still singular, requiring a singular verb.