Q. I’ve always thought that when you use any as a pronoun it should be treated as singular. But in the following sentences, “Do they all match? Is any missing?” using is feels awkward. Does any in this case refer to they in the previous sentence?
A. Yes, it does. Any can be singular or plural (which I’m sure by now you have learned from checking the dictionary you keep at hand): “Have you checked the pizza? Is any missing?” or “Have you checked the Twinkies? Are any missing?” Both are correct (and around here, most likely missing).