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In English grammar, number indicates a word is singular or plural.

In English sentences, subjects and verbs must agree in number. Such agreement is typically called subject-verb agreement. So if the subject is singular, the verb must be singular or if the subject is plural, the verb must be plural.

Singular Forms for Nouns
and Present Tense
3rd Person Verbs
Plural Forms for Nouns
and Present Tense
3rd Person Verbs
Singular nouns have no –s. Many nouns become plural by adding -s
Singular present tense verbs require the –s. Plural present tense verbs are pluralized by removing the –s.
The boy eats.
The girl plays.
The baby swims.
The boys eat.
The girls play.
The babies swim.

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