The subject and the verb in a sentence must work together, or agree.
To make most present tense verbs agree with singular nouns or he,
she, or it, add -s or -es.
If the subject is a plural noun or I, you, we, or, they, the present tense verb does not end in -s.
Singular Subjects: Night follows day. He watches the sunset.
Plural Subjects: Nights give us darkness. We light a candle.
Use is or was to agree with singular nouns. Use are or were to agree
with plural nouns.
Singular Subjects: Night is cool and dark.
Plural Subjects: The night beasts are free.