Question

What is the basic principle in subject-verb agreement?

Answer 1

the correct answer is B!!

Answer 2

Answer:
B. Singular subjects need singular verbs while plural subjects need plural verbs.

The agreement consists in that the number of the verb and the number of the subject need to be the same: if the subject is singular the verb has to be singular, and if the subjetc is plural the verb has to be plural.

Verb-subject disagreement is a grammatical error.