Usage and Grammar
Q. When providing options between two or more singular items and one or more plural items, should a writer use a plural verb or a singular verb? For example: “When Mom or Dad or both [say/says] no, you’d better stop asking.”
A. Grab the nearest noun or pronoun in the series and use it to determine the verb:
When Mom or Dad or both say no, you’d better stop asking.
When your parents or the babysitter says no, you’d better stop asking.