This document provides 20 rules for subject-verb agreement in English. Some key points covered are: singular subjects require a singular verb and plural subjects require a plural verb; prepositional phrases between the subject and verb do not usually affect agreement; subjects can come after the verb in questions; collective nouns and units of measurement usually take singular verbs; and indefinite pronouns like everyone and anybody take singular verbs. The document stresses that only the subject, not other words in the sentence, determines if the verb is singular or plural.