Speak good English: the use of either...or and Neither... nor

We learnt that we use a singular verb with either...or and neither...nor when the two items mentioned are both singular.

Egs: Either my dad or my mum has arrived.

Neither the teacher nor the student knows the answer to the question.

When both items mentioned are plural, we use a plural verb with either...or and neither...nor.

Egs: Either my parents or my siblings have arrived.

Neither the teachers nor the students know the answer to the question.

Now, what do we do when one of the items mentioned is singular while the other is plural?

Egs: Either my mum or my siblings ... arrived.

Neither the students nor the teacher ... the answer to the question.

 In situations such as the above sentences present, we apply what we call PROXIMITY CONCORD.

The word PROXIMITY means CLOSENESS or NEARNESS and in proximity concord, it is the item closer or nearer to the verb that determines whether the verb should be singular or plural.

For instance, in the first sentence above:

Either my mum or my siblings ... arrived

the item closer to the verb is plural --- siblings --- and so the verb should be plural.

So that sentence should be:

Either my mum or my siblings have arrived.

This sentence could also be written as:

Either my siblings or my mum has arrived.

This is because this time it is the singular item mum that is closer to the verb, for which reason the verb should be singular.

In the second example above: Neither the students nor the teacher ...

the answer to the question the item closer to the verb is teacher, which is singular, and so the verb should be singular as in:

Neither the students nor the teacher knows the answer to the question.

Once again, note that that sentence could be written as: Neither the teacher nor the students know the answer to the question.

Other examples of the application of proximity concord are: Either Kofi or his friends were late to school yesterday.

Neither the man nor his wives are home. Either the girls or the boy is telling a lie. Neither the boy nor the girls were at the party.