This document discusses subject-verb agreement rules in English grammar. It explains that the subject of a sentence determines whether the verb is singular or plural. It provides 17 rules for determining agreement, such as whether compound subjects joined by "and" or "or" require a singular or plural verb. It then provides 23 examples for the reader to choose the correct verb form based on the subject. The document serves as a guide for non-native English speakers to properly select verb forms according to subject-verb agreement principles.