Subject-verb agreement: either, neither, nor, or

Two singular nouns connected by or or nor take a singular verb.

• Neither Charles nor Benjamin was present there.
• Neither he nor his dad is good at driving.

When one of the nouns connected by or or nor is plural, the verb must be plural, and the plural subject must be placed next to the verb.

• Neither Peter nor his parents were aware of this. (More natural than ‘Neither his parents nor Peter was aware of this.)

When the subjects connected by or or nor are of different persons, the verb agrees with the noun that comes closer to it.

• Neither you nor he is responsible for this. (Here the verb is agrees with the third person pronoun he.)
• Either he or you are to clean up the mess. (Here the verb are agrees with the second person pronoun you.)
• Either you or John has to pay for the drinks.

The determiners each, every, anybody, every one etc.

The determiners each, every, every one, anybody, either, neither, no one, nobody and many a should be followed by a singular noun and a singular verb.

• Many a man has lost his life at sea. (Here the expression many a is followed by a singular noun and a singular verb.)
• Neither candidate is fit for the job. (NOT Neither candidates are fit for the job.)

We cannot put a noun immediately after every one. Instead we use the structure every one of. Every one of should be followed by a plural noun and a singular subject.

• Every one of the boys seems to be excited about the picnic. (NOT Every one of the boy seems…) (NOT Every one of the boys seem…)