who与whom有什么不同?whoever与whomever有什么不同?

关系代词who与whom 的用法区别 两者均只用于人,从理论上说,who 为主格,whom为宾格.如：Where’s the girl who sells the tickets?卖票的女孩在哪里?The author whom you criticized in your view has written a letter in reply.你在评论中批评的那个作者已写了一封回信.但实际上,除非在正式文体中,宾格关系代词 whom 往往省略不用,或用who或that代之.如：The man (that,who,whom) you met just now is called Jim.你刚遇见的那个人叫吉姆.不过,在以下几种情况值得注意.如：(1) 直接跟在介词后面作宾语时,只能用 whom,而且不能省略.如：She brought with her three friends,none of whom I had ever met before.她带了brought with her three friends,none of whom I had ever met before.3个朋友来,我以前都没见过.(2) 引导非限制性定语从句且作宾语时,who 和 whom均可用,但以用 whom 为佳,此时也不能省略.如：This is Jack,who [whom] you haven’t met before.这是杰克,你以前没见过
从形式上来看,who(ever)是人称代词的主格形式,一般在句子中作主语；
whom(ever)是人称代词的宾格形式,故一般作宾语.一般说来,whomever不能做句子的主语.