1、who, whom, that
限定性定语从句中的关系代词
作主语 作宾语 作定语
指人 who/that whom/that(可省略) whose
指物 which/that which/that(可省略) whose
指人和物 that that whose
非限定性定语从句中的关系代词
作主语 作宾语 作定语
指人 who whom whose/of whom
指物 which which whose/of which
特殊情况：
只能用that的情况,
先行词为everything,all,little,much等不定代词时；
先行词被all,every,no,any,some,little,much修饰时；
先行词被the only,the very,the same,the last修饰时；
先行词被序数词或形容词最高级修饰时；
先行词是be的表语或there be 的主语时；
先行词有人又有物时；
当主句是以who或which开头的特殊疑问句时.
不能用that的情况
介词前置时；
非限定性定语从句中
这些词代替指人,whom在定语从句中指人,"who"和“that”既可作主语又可作宾语（作宾语可以省略）,可以指人也可以指物（who不可指物）.在从句中所起作用如下：
（1）Is he the man who/that wants to see you? 他是那个想见你的男人吗?（who/that在从句中作主语）
（2）He is the man （whom/that） I saw yesterday. 他就是我昨天见到的那个人.（whom/that在从句中作宾语）
（3）The man whom you spoke to just now is our English teacher. 刚刚和你说话的那个男人是我们的英语老师.（whom在从句中作宾语）
注：who在定语从句中指人,作主语和宾语,作宾语时可省略；做及物动词或介词的宾语,可省略. [1]2,which,that 用来指物（有六种情况只可用that而不用which）
(用作主语、宾语,作宾语时可以省略）,例如：
（1）The prosperity which/that had never appeared before took on in the countryside.农村出现了前所未有的繁荣.（which/that在从句中作主语）
（2）The package (which/that) you are carrying is about to come unwrapped.你拿那个包裹快要散开了.（which/that在从句中作宾语）
注：which在定语从句中指物,可作主语或及物动词或介词的宾语,作宾语时可省略；that在定语从句中既可指人又可指物,在定语从句中作主语、宾语和表语,作宾语时可省略,指人时,相当于who或whom,指物时,相当于which,作介词宾语时,介词不可提到that前,当介词提前时,需要用which或whom来代替.[1]2、whose
(只用作定语)
“whose”表示谁（可以为人也可以为物）的（东西）
例：A child whose parents are dead is called an orphan.双亲都死了的孩子叫做孤儿.（“whose parents”表示那个孩子的双亲）
He lives in a room whose window faces south.他住的那个房子的窗户是朝南的.（“whose”表示那个房子的窗户）
关系代词：在句中作主语、宾语或定语.
1. that既可代表事物也可代表人,“which”代表事物；它们在从句中作主语或宾语,作宾语可省略“that”在从句中作宾语时常可省略关系词,“which”在从句省略.[eg：This is the book （which）you want.]
2.不及物动词+介词”的介词的宾语代词“which”放在它原来的位置.
3. 代表物时多这时的that常被省略；
c）被形容词最高级修饰时；既有人又有物时；
e）整个句中前面已有“which”,“why”行
关系副词：在句中作状语
关系副词=介词+关系代词
why=for which
where=in/ at/ on which（介词同先行词搭配）
when=during/ on/ in/……
1. “where”是关系副词,当然也不用“that”引导.
By the time when you arrived in London, we had stayed there for two weeks. 当你到达伦敦的时候,我们在那里已经待了两个星期.
I still remember the place where I met her for the first time. 我仍然记得我第一次见到她的地方.
Each time when he goes to business trip, he brings a lot of living necessities, such as towels, soap, toothbrush etc. 他每次出差都带着生活必需品,如毛巾,肥皂,牙刷等其他东西.
2. 当从句的逻辑主语是some, any, no, somebody, anybody, nobody, something, anything, everything或nothing时,常用“there is”开头.
There is somebody here who wants to talk to you. 这里有人要和你说话.
分作进一步说明,通常是引导词和先行词之间用逗号隔开,将从句拿掉后其他部分仍可成立.
编辑本段关系副词
1、why
关系副词why主要用于修饰表原因的名词（主要是the reason）,同时它在定语从句中用作原因状语.如：
We don’t know the reason why he didn’t show up. 我们不知道他为什么没有来.
She didn’t tell me the reason why she refused the offer. 她没跟我讲她拒绝这项工作的原因.
与关系副词when和where不同,why可以换成that或省略.如：
That’s one of the reasons (why, that) I asked you to come. 这就是我请你来的原因之一.
另外,与关系副词when和where可以引导非限制性定语从句不一样,why只能引导限制性定语从句,不能引导非限制性定语从句.如：
他失去工作的主要原因是他喝酒.
误：The main reason, why he lost his job, was that he drank.
正：The main reason why he lost his job was that he drank.(同位语从句)
2、when
关系副词when主要用于修饰表时间的名词,同时它在定语从句中用作时间状语.如：
There comes a time when you have to make a choice. 你必须作出抉择的时候到了.
Gone are the days when they could do what they liked. 他们为所欲为的日子一去不复返了.
We’ll put off the picnic until next week, when the weather may be better. 我们将把野餐推迟到下星期,那时天气可能会好一点.
注意不要一见到先行词为时间名词,就以为一定要用关系副词when来引导定语从句,同时还要看它在定语从句中充当什么成分——如果在定语从句中用作时间状语,就用when；如果在定语从句中不是用作时间状语,而是用作主语或宾语,那就不能用when,而要用that, which等.如：
Don’t forget the time (that, which) I’ve told you. 不要忘记我告诉你的时间.
关系代词that / which在定语从句中用作动词told的宾语,正因为是用作宾语,所以也可以省略.
3、where
关系副词where主要用于修饰表地点的名词,同时它在定语从句中用作地点状语.如：
This is the village where he was born. 这就是他出生的村子.
That’s the hotel where we were staying last summer. 这就是我们去年夏天住的旅馆.
Barbary was working in Aubury, where she went daily in a bus.巴巴拉在奥伯里工作,每天得坐公共汽车去上班.
与前面when的情况一样,注意不要一见到先行词为地点名词,就以为一定要用关系副词where来引导定语从句,同时还要看它在定语从句中充当什么成分——如果在定语从句中用作地点状语,就用where；如果在定语从句中不是用作地点状语,而是用作主语或宾语,那就不能用where,而要用that, which等.如：
He works in a factory that [which] makes TV sets. 他在一家电视机厂工作.
关系代词that / which在定语从句中用作主语.
另外注意,where有时还可用于抽象名词后引导定语从句.如：
We have reached a point where a change is needed. 我们到了必须改一改的地步.
There are cases where the word “mighty”is used as an adverb. 在一些情况下,mighty一词可用作副词.
He got into a situation where it is hard to decide what is right and wrong. 他陷入一种难以分辨是非的局面.
I don’t want a job where I’m chained to a desk all day. 我不想找一份整天坐办公桌前的工作.
