Identifying the subject and the verb is the first step in correcting subject-verb agreement errors. The verb agrees in person and number with its subject.
The subject and the verb must agree in number.
A singular subject (one person or thing) takes a singular verb.
The bird sings.
The wheel turns.
The student reads.
A plural subject (more than one person or thing) takes a plural verb.
The birds sing.
The wheels turn.
The students read.
From these examples, or from a review of verb endings in Chapter 2, it should be clear that the singular verb in the present tense ends in -s.
A subject and a verb agree if you use the correct form of the verb with the subject. Add an -s to the singular verb in the present ...