Singular verb is a verb that agrees with the singular subject. In simple present tense, the singular verb has -s or -es added to the main verb.
Example: The girl goes to school everyday.
The subject "girl" is singular.
The verb goes (go) is a singular verb
Plural Verb is a verb that agrees with the plural subject. The main verb remains unchanged in simple present tense when the subject is plural. The pronouns "you and I' are considered plural subject even if it represents only one person.
Example: My dogs bark at strangers.
The subject "dogs" is plural.
The verb "bark" agree is a plural verb.