who whom的用法

who whom 都指代人.who 可作定语从句的主语和宾语,whom只作宾语.
作宾语时who/ whom都可以省略 .
当关系代词前有介词时,用介词+Whom 结构.如
He is the boy who came to our class yesterday
He is the boy (who / whom) I helped yesterday
He has a sister of whom he is proud
who whom 都指代人.who 可作定语从句的主语和宾语,whom只作宾语.
作宾语时who/ whom都可以省略 .
当关系代词前有介词时,用介词+Whom 结构.如
He is the boy who came to our class yesterday
He is the boy (who / whom) I helped yesterday
He has a sister of whom he is proud

用在介词后只能用whom

1.who 先行词指的是人，在从句中作主语和宾语
如：主句：The lady is very beautiful
从句：The lady is sitting under the tree.
先行词为人，the lady, 在从句中作主语，改写成定语从句就是：
The lady who is sitting u...

whom 是 who 的宾格。
who are you?
From whom shall I get comfort?