When talking about agreement of subject and verb, the identifying word is number. Number refers to the form of a word that indicates whether it is singular
or plural. A verb must agree with its subject in number. A little practice can make Subject/Verb agreement second nature when one is writing, so that if there is disagreement in a sentence it immediately shows up in proof reading, or ideally, when it is being written.

Singular subjects indicate one and require a singular verb. Plural subjects indicate more than one and require a plural verb. Here is the key to remember. Most regular verbs add

s or es to form the singular. Note that this is opposite to forming singulars with nouns, so dont confuse verbs with nouns in these cases.

Example: Singular: The author writes. The champion boxes.

Example: Plural: The authors write. The champions box.

An exception top the rule occurs with the pronouns I and you. Both take the plural form of a verb, even when you refers to one person. The only exception is be; whenI is the subject, the verb form is am.

Example: I eat breakfast.

Example: You prepare dinner.

Whether functioning as main verbs or auxiliary verbs, be, have, and do change in form to show agreement. In fact, the number of a verb phrase is indicated by these auxiliary verbs.

Examples: Singular I am late. He is laughing. The applicant has experience. She has listened intently. Does he need help? Notice in the verb phrases the main verbs do not change form.

Examples: Plural. We are late. We are laughing. The applicants have experience. They have listened intently. Do they need help?

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