一、意思不同
1、who为主格人称代词,who 用作主语、宾语和表语;
2、whom为宾格人称代词,whom用作宾语,在口语中,有时可用who代替whom,who和whom做宾语时可省略。
二、用法不同
whom是who的宾语格式,只能做宾语。who 可以做主语,又可以做宾语。
例句:Who has the biggest ears in your family?
你们家谁的耳朵最大?
Whom did you invite?
你邀请了谁?
三、侧重点不同
介词提前,介词后必须用且只能用whom不用who,这里引导词同样当宾语,但是位于介词to后,只能用whom,而不能用who(that同样不行)。
例句:there is nobody to whom he can turn for help。
这里没人能帮他。
who和whom在从句中分别作主语和宾语,指人其中 who可以替换whom,但是介词后面一定要用whom。
例:I want to know whom/who you are waiting for?
I want to know for whom you are waiting?
who 在宾语从句中做主语,whom 只做宾语。