Subject-Verb Agreement

Core Rules of Agreement and Intervening Words

At the foundation of English grammar is the principle that a subject must agree in number with its verb. A singular third-person subject generally takes a singular verb, while a plural subject requires a plural verb. Note that singular 'I' and 'you' follow different agreement patterns. In the simple present tense, third-person singular verbs typically end in '-s' or '-es'. In contrast, plural subjects in the simple present tense do not take the third-person singular '-s' or '-es' verb ending.

A common challenge arises when additional words sit between the subject and its verb. A prepositional phrase between the subject and the verb does not change the number of the subject. Furthermore, a prepositional phrase between a subject and its verb does not contain the subject of the main clause. Even if the noun inside the prepositional phrase is plural, a singular subject still requires a singular verb.

Similarly, phrases introduced by 'as well as', 'along with', 'together with', or 'in addition to' do not alter subject-verb agreement. Parenthetical expressions separated by commas do not affect whether a subject is singular or plural. Writers must locate the true subject of the clause and disregard these intervening modifying phrases when choosing the correct verb form.

Agreement also applies strictly to the true subject rather than to following complements. The linking verb 'to be' agrees with its subject, never with the predicate nominative. Even when a singular subject is followed by a plural predicate nominative, or a plural subject is followed by a singular predicate nominative, the verb must match the subject itself.