Vejam o exemplo abaixo:
Neither this nor that is/are what I'm looking for.
Neither this nor that works/work fine.
Qual é a forma correta ?
Um guia para quem estuda Inglês Online
Either/or and neither/nor
1.Either / or - used in a sentence in the affirmative sense when referring to a choice between two possibilities
We can either eat now or after the show - it's up to you.
2. Neither / nor - used in a sentence in the negative sense when you want to say that two or more things are not true
Neither my mother nor my father went to university.
Singular or plural
When using either/or and neither/nor, note the following rules:
1. If both elements are singular, then the verb is singular too.
Either the father or the mother has to attend the meeting. (father and mother are singular; so the verb has is singular too)
Neither Leila nor Nancy is going to write the report. (Leila and Nancy are singular; so the verb is is singular too)
2. However, if one of the elements is plural, then use a plural verb.
Either Sue or the girls are going to prepare dinner tonight. (the girls is plural; so the verb are is plural too)
Neither the teacher nor the students were in the classroom this morning. (the students is plural; so the verb were is plural too)