Here are a few things to remember for subject-verb agreement

Singular subjects joined by or or nor

If a sentence begins with two singular subjects that are joined by the words or or nor then you have to use a singular verb

Example; Robert or William chooses the team captain.

Singular subjects joined by neither/ nor or either/or

If the sentence has two singular subjects that are joined by the words neither/nor or either/or you should use a singular verb.

Example; Neither Kelly nor Alexandra is going camping this year.

Either Sandra or Harry closes the meeting every day.

Subjects that contain a singular and plural noun or pronoun (Compound Subjects)

If a compound subject has a singular noun/ pronoun and a plural noun/ pronoun joined by the words or or nor then the verb agrees with the subject closer to it.

Example; The students or a teacher greets the parents at the gate.
The singular noun (teacher) is closer to the verb so we use the singular form (greets).

A teacher or the students greet the parents at the gate.
The plural noun (students) is closer to the verb so we use the plural form (greet).

Neither Sandra nor the boys were here early today. The plural noun ‘boys’ is closer to the verb so we use the plural form (were)

Neither the boys nor Sandra was here early today.
The singular noun Sandra is closer to the verb so we use the plural form (was)

Subjects joined by and

If two or more nouns or pronouns are joined by the word and you should use a plural verb.

Example; My brother and sister are on the debate team.

Alice and Mary were at the playground.

Abeiku and I are best friends.

Did you notice that in each sentence both subjects are singular but we still used the plural verb?

Subjects separated by a phrase

If a subject and verb are separated by a word or phrase, the verb still has to agree with the subject, even if there is a noun or pronoun in the phrase.

Some of these phrases are

as well as

in addition to

along with

together with

accompanied by

with

To make this clearer, let us look at a few examples:

Example;

The teacher, as well as the students, was impressed by Mabel’s essay.

Naa, together with her family, visits the museum every vacation.

The bully, along with his friends, was no match for Terry.

Betsy, accompanied by her dog, runs for twenty minutes every morning.