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

Regular verbs (with forms that follow standard English patterns) have two forms in the present tense: one that ends in -s and one that has no ending. The third-person subjects — he, she, it — and singular nouns always use the form that ends in -s. First-person subjects (I ), second-person subjects (you), and plural subjects use the form with no ending.

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