Subject-verb agreement means that the subject and the verb of a sentence match in number and person. For example, if the subject is singular, the verb should also be singular. If the subject is plural, the verb should also be plural. Subject-verb agreement can be tricky when the subject is a collective noun, a compound noun, or an indefinite pronoun. For example, the collective noun "team" can be either singular or plural, depending on whether you want to emphasize the group as a whole or the individual members. The compound noun "coffee and tea" is plural, while the compound noun "bread and butter" is singular. The indefinite pronoun "everyone" is singular, while the indefinite pronoun "some" can be either singular or plural. To avoid errors, identify the subject and the verb of each sentence and make sure they agree.