A who，whom在正规英语中我们用介词+whom结构：With whom did you go？你和谁一起去的？To whom were you speaking？你刚才在跟谁说话？但在日常口语中我们常把介词置于句末。这时一般将whom变成who：Who did you go with？Who were you speaking to？B which，what在正规英语中我们用介词+which/what结构：To which address did you send it？你把东西寄到哪个地址去了？On what do you base your theory？你的理论依据是什么？在非正规英语中我们将介词置于句末：Which address did you send it to？What do you base your theory on？