Problems with Subject-Verb Agreement

In any sentence, the subject and the verb must match — or agree — in number. If the subject is singular (one person, place, or thing), then the verb must also be singular. If the subject is plural (more than one), the verb must also be plural.

SINGULAR The phone rings constantly at work. [The subject, phone, is singular — just one phone — so the verb must take the singular form: rings.]
PLURAL The phones ring constantly at work. [The subject, phones, is plural — more than one phone — so the verb must take the plural form: ring.]

For more on regular verbs and how they differ from irregular verbs, see “Regular Verbs.”

Regular verbs follow standard English patterns. For regular verbs in the present tense, only third-person singular verbs take an ending, and that ending is -s.

Regular Verbs, Present Tense

SINGULAR FORM PLURAL FORM
First person I walk. We walk.
Second person You walk. You walk.
Third person He/she/it walks. They walk.
Percy walks. Percy and Don walk.
The dog walks. The dogs walk.

To find problems with subject-verb agreement in your own writing, look for the five trouble spots that follow.