Hercules and Pedro trains together for the Olympics. What is the error in the subject verb agreement

Hercules and Pedro train together for the Olympics.

Explanation:

The subject-verb agreement refers to the agreement of the subject(s) and the verb(s) in a sentence in number. This means that a singular subject must use a singular verb while a plural subject must use a plural verb.

In the given sentence, the subject is plural "Hercules and Pedro" while the verb used is singular "trains". This is wrong for a singular subject will have a singular verb and a plural subject will have a plural verb.

So, the error of subject-verb agreement is in the "Hercules and Pedro trains". The correct subject-verb agreement will be-

Hercules and Pedro train together for the Olympics.

answer; (external conflict)