Subject-verb agreement

In any complete English sentence, there must be a subject and a verb.

• The verb is the action in the sentence. (E.g. I am downstairs.)
• The subject is the person or thing that does the action. (E.g. I am downstairs.)

Subject-verb agreement, then, is all about numbers. Does the verb form chosen match up with the number of things in the subject?

• Singular subjects take singular verbs. (E.g. I am downstairs.)
• Plural subjects take plural verbs. (E.g. We are downstairs.)

This being English, there are of course many exceptions to the rule. However, two in particular are quite common.

• When two subjects are connected by and, the subjects should be treated as plural.

Example

E.g. John and Todd are downstairs. The word "and" joins the two subjects, so we use the plural form of the verb.

• When two subjects are connected by or, use the subject that is closest to the verb to determine agreement. 

Examples

Either John or Todd is downstairs. "Todd" is closest to the verb, so the verb agrees with the singular "Todd."

Either John or the twins are downstairs. "The twins is closest to the verb, so the verb agrees with the plural "the twins."

While there are additional exceptions, this covers the basics. Following these steps will help ensure that you always have subject-verb agreement.

Subject-verb agreement is one of the most basic parts of English, yet it contains all sorts of pitfalls for the writer. Reviewing the materials above will help you more fully understand subject-verb agreement and avoid many of the common mistakes that can occur in writing.