What size are your feet?
老美在口语上也会说 What size feet do you have?
(听起来有点怪, 好像该说 What size of feet do you have?
但它在口语上的确就只要说 What size feet 就好了)
更口语的还有 What size feet you got? (= What size feet have you got?)
( have got, has got = have, has )
要讲 What size shoes do you wear? 或 What size are your shoes? 也没有错
只是若今天是一个老美要表达这个意思时
脱口而出的通常会是 What size feet do you have? / What size are your feet?