Q. I think this is correct: “We may recognize whether any of our friendships is truly spiritual.” My boss thinks it should be are: “whether any of our friendships are truly spiritual.” I can’t find a reference to this in the CMOS except that indefinite pronouns typically are treated as singular when followed by a verb.
A. Any can serve as singular or plural. If more than one of your friendships could be spiritual, then any is plural and you need are. In a sentence where any must be singular, use is: If any of this Twinkie is gone when I get back, there’ll be hell to pay.