Does question word "Who" always require a singular verb right after it?
Imagine a situation, in which somebody is telling you a sentence, but you don't make out one word in it (in the example below that word is shown by XXXXX):
-- I just realized that those XXXXX go to school only 3 times a week!
On one hand, you didn't hear the word clearly, but, on the other hand, you did hear "those" (not "that") and "go" (not "goes"), so you are quite positive that it's about more than one person. So, how would you ask a question here?
Would you ask like:
-- I am sorry I didn't hear it. Who go to school only 3 times a week?
or would you still stick to the singular form (even though you know that it's more than one person meant) like:
-- I am sorry. I didn't hear it. Who goes to school only 3 times a week?