(1) 关系代词who,whom,whose,that,which,as的用法
  英语中的关系代词有who,whom,whose,that,which,as,它们是用来引导定语从句的。关系代词既代表定语从句所修饰的词,又在其所引导的从句中承担一个成分, 如主语、宾语、表语或定语。如:
This is the man who saved your son.
这就是救了你儿子的那个人。(who在从句中作主语,先行词是man)
The man whom I met yesterday is Jim.
我昨天见到的那个人是吉姆。(whom在从句中作宾语,它的先行词是man)
He wants a room whose window looks out over the sea.
他想要个窗户面临大海的房间。(whose在从句中作定语,它的先行词是room)
I walked to the gate that opened towards the lake.
我走向那扇临湖的大门。(that在从句中作主语,它的先行词是gate)
This is the pen which he bought yesterday.(which在从句中作宾语,它的先行词是pen,可省略)
As is known to everybody, the moon travels round the earth once every month.
众所周知,月球每个月绕地球转一周。(as在从句中作主语,指代主句)
(2)关系代词who,whom,whose的区别
a) who和whom均只用于指人,不用于指事或物,其中who在定语从句中用作主语,whom在定语从句中用作宾语。Who有时可代替whom作宾语,但在介词后面一定要用whom作介词的宾语。如:
She said she huffed the persons who flattered her.
她说她看不起那些拍她马屁的人。
The man who / whom you met just now is called Jim.
你刚遇见的那个人叫吉姆。
She brought with her three friends, none of whom I had ever met before.
她带了3个朋友来,我以前都没见过。
b)关系代词whose既可用于指人,也可用于指事或物,它在定语从句中主要用作定语。如:
This is the woman whose name is known all over the country.
这个是一个名字被整个国家所熟知的女科学家。