When I reviewed my answer above, I realized that the rule applies to "two singular subjects", however, in your question the subject was not connected by "or, either/or, or neither/nor". So, I did a little more research by consulting the book called "Practical English Usage." The following is an excerpt from the book: Determiners When "none, neither, either and any" are followed by "of + plural noun/ pronoun", they are normally used with singular verbs in a formal style in British English. Plural verbs are common in informal British usage and generally in American English. - None of the cures really works. (formal British) - None of the cures really work. (informal British; American) - Neither of my brothers has/have been outside England. - Has/Have either of them been seen recently? - If any of the children gets/get hungry, they can have an orange. So, Neither of them IS (Formal British English) Neither of them ARE (Informal British and American English)

I am not sure if there is a rule that you must use one and not the other. To my ear, "are" sounds a bit better. I think you will probably see "is" also from native speakers.

Actually, there is a grammar rule related to the subject-verb agreement, i.e., the verb must agree with the subject, both in "the person" and in "singular or plural" subjects. The rule is described in this excellent website: http://www.grammarbook.com/grammar/subjectVerbAgree.asp Rule 2. Two singular subjects connected by "or, either/or, or neither/nor" require a singular verb. Examples: My aunt or my uncle is arriving by train today. Neither Juan nor Carmen is available. Either John or Casey is helping today with stage decorations. .... NEITHER OF THEM IS... (A is not and B is not)

A. neither/nor ;either/or; not only/but also follow the proximity rule: 5) Either the President or the three senators are going to speak …. 6) Either the three senators or the President is going to speak … (https://magoosh.com/gmat/2014/compound-subjects-additive-phrases/) B.Neither is always singular: Neither of them is... https://magoosh.com/gmat/2013/gmat-sentence-correction-indefinite-pronouns-and-agreement/ C.'None' depends on what the subject is(described in same link above) None of the students are.. None of the milk is....

Thank you, desertjedi. Phil, if I wanted to sound Spanish, I'd just say "ninguno de los dos." Thanks for the advice.