Whom did you see?为什么用whom而不用who说清楚一点 我不懂

Whom did you see?为什么用whom而不用who说清楚一点 我不懂 who,whom are they talking about?还有who,whom did you see?答案上都用的whom,我觉得应该是who, did not you see the man（ 为什么要用I nodded to just now?而不用I nodded just now?whom I nodded just now? Did not you see the man i nodded to just now?这里面为什么不要whom呢?不是应该是定语从句么 可以省略 Did you see the person_____new motorbike was stolen A.whom B.who C.which D.whose whom never will you see? Did you see the man___?A.I nodded just now B.whom I nodded just nowC.whom I nodded to him D.whom I nodded to just now did you see my 白得的分本人英语很菜,You saw whom?可不可以改成 who did you see? write about a museum you have visited.with whom did you go?what museum is it?what did you see there? Did you see the man______?A I nodded just now B whom I nodded to him C whom I nodded to just now I saw him.Whom did you see?That man?Yes,he's the man whom I saw.帮我看看句子有没有错 Did you see the accident happenDid you see the accident ________ 是happen 还是happened,为什么 ----did you say would understand it?A whoB whom选哪个,为什么 What animals did you see? Did you see the doctor? did you ever see snow? what ()did you see填空