Each subject linked by the conjunction “and” records a plural text. The wolves of the pack live in the nearby forest. “Packs” is the theme and is in the plural, and so the verb is “live”, which is paired with. If the subject is composed of coordinated substantive sentences, the overrealization of the verb corresponds to the second substantive sentence, if they differ in number. The theme of cats are plural and therefore the verb is persecution. In contrast, prepositional sentences refer to a group of words that contain no verb or subject and function as a single part of a speech. For this sentence, the subject is “his little sister” and the verb is “to play”. What is remarkable is that the principles of subject-verb agreement only apply to finite verbs [the link leaves this page] that are in the present tense and, in a way, to the past form of verbs to be, as it was and was. . . .