what is the different between who and whom ?

who同whom 都是指 "誰"
(whose才是 "誰的")

兩者的分別是：
1. who is used as the subject(主語) of the sentence/clause
The old man who live next door is 70 years old. (主語是the old man)

2. whom is used as the object(賓語) of the sentence/clause
The boy whom we met is Susan's brother. (object賓語是the boy)

不過，現在很多時我們都唔會再分who/whom 。 我們大多數用who，意思是who可以取代whom，不用再細分了。

2. past perfect and present perfect

1. present perfect (have/has + p.p) 是以前發生的事對現在還有影響力
I have known her for 3 years. (你現在還認識她)
She has learnt to play the piano since 2001.(由01年到現在還學琴，顯示持續性)

2. past perfect (had + p.p) 要同past tense一齊用，目的是顯示過去所發生的事情之先後次序：
After she had taken a shower, she started to do her homework.
I didnt see him. He had left when I arrived.

past perfect用以強調past actions既先後次序，所以較少用。




1.)Whom

pron.(who的受格,用在正式的講話及書面語中)
1. (用作疑問代名詞)誰,什麼人
I know who you are and whom you represent.
我知道你是誰並代表誰。
2. (用作限定關係代名詞)...的人
I'll give my vote to the man in whom I have faith.
我將把我的選票投給我所相信的人。
She was the girl whom you met at the airport.
她就是你在機場遇見的那個女孩。

2.)Who

pron.
1. (用作疑問代名詞)誰,什麼人
Did Mary tell you who that girl's father is?
瑪麗有沒有告訴你那女孩的父親是誰?
Who has borrowed my pen?
誰借了我的鋼筆?
2. (用作限定關係代名詞)...的人
The girl who spoke is my best friend.
那講話的女孩是我最好的朋友。
3. (用作非限定關係代名詞)他;她;他們;她們
I went to the movies with Mary, who I think you once met.
我與瑪麗一起去看電影。我想你見過她。
4. 【古】(省略先行詞的關係代名詞)...的人

3. (用作非限定關係代名詞)他,她;他們,她們
My new neighbor, whom I introduced to you the other day, had a heart attack last night.
日前我介紹你認識的我那位新鄰居昨晚心臟病發作。
4. 【古】(省略先行詞的關係代名詞)...的人

who is active voice
whom is indirectly
For instance , the man who wears a dress is tom.
the pen whom is tom is blue.