This document discusses the basic rules of subject-verb agreement in English grammar. It outlines several rules:
1) A singular subject takes a singular verb and a plural subject takes a plural verb.
2) In inverted sentences where the verb precedes the subject, the verb still agrees with the subject.
3) When there are inverting phrases or clauses between the subject and verb, the verb agrees with the subject, not other words in the phrase.
4) Some irregular nouns can be either singular or plural depending on their meaning in the specific context. Collective nouns also take a singular or plural verb depending on whether the group is being treated as a unit or individuals.