In this example, “man” is a singular, masculine noun, so “to be” is the appropriate pronoun to replace the noun. “In English, the agreement is relatively limited. It occurs between the subject of a sentence and a prefix, so that for example.B. for a singular subject, the verb must have the suffixe-s in the third person (for example. B John). That is, the verb corresponds to its subject by having the corresponding ending. So John drinks a lot of grammar, but John drinks a lot is not grammatically as a sentence in itself, because the verb does not match. In this example, politics is a unique theme; Therefore, the sentence has a singular verb.. . .