(1) What size shoes do you wear?
(2) What size of shoes do you wear?
We are told that most American and British speakers say No. l.
If we learners chose No. 2 on an examination, would the teacher be justified if she or he marked the answer as "wrong" and refused to give us credit?
I think that most people ask: "what's your shoe size?"
Thank you very much, Moderator Bhaisahab and Teacher John.