定语从句中关系词的作用：1.指代被定语从句所修饰的名词或代词（即先行词）；2.在从句中作句子成分。
一、限制性定语从句关系代词的选择：who whom whose which that
1.作主语：多数用情况下使用who指人 、that指物 ；
2.作宾语：在正式语体中whom指人、which指物；
3.作定语:whose指人、或指物（=of whom）
4.作介词宾语：在正式语体中，介词通常前置，whom指人, which指物。（限制和非限制都可）
注意要点：
1.
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定语从句中关系词的作用：1.指代被定语从句所修饰的名词或代词（即先行词）；2.在从句中作句子成分。
一、限制性定语从句关系代词的选择：who whom whose which that
1.作主语：多数用情况下使用who指人 、that指物 ；
2.作宾语：在正式语体中whom指人、which指物；
3.作定语:whose指人、或指物（=of whom）
4.作介词宾语：在正式语体中，介词通常前置，whom指人, which指物。（限制和非限制都可）
注意要点：
1.
作介词宾语指人用(介词+whom )；指物用(介词+which)；
2.作直接宾语的关系代词可以省略；
3.定语从句中关系代词的单复数取决于先行词的单复数；
4.that仅用于限制性定语从句中；而who whom whose which即可用于限制性定语从句中，也可用于非限制
e.g
1.He's the man who/that lives next door to us.
2.Where is the man (whom/who/that) I saw this morning ?
3.Do you know anyone whose family is in xi'an ?
4.James is a man for whom I have the greatest respect .
For mor examples:
使用要点：
1.先行词本身是all,much,everything,something,nothing,anything,little,none等指物的不定代词时关系代词一般只用that，不用which；
Anything that can burn is a source of heat energy.
That's all (that) I could do at that time.
There is little that can be believed about it.
She has nothing that is good to say.
The book doesn't say much that amuses children.
She hates everything that is modern.
2.如果先行词是anyone, anybody, everyone, everybody, someone, somebody, nobody, no one,应用who或whom，不用which；
Is there anyone here who can speak English?
I saw the manager talking with somebody whom he didn't know.
3.先行词被序数词、形容词最高级，以及first,the last,the only,any,few,much,no,some,every等修饰时关系代词常用that，不用which/who/whom；
This is the most impressive TV theater that has never been put on show before.
He is the only person that was present at the time.
This is the best TV set that is made in China.
No sample that we have received is satisfactory.
Please send us any information that you have about the subject.
4.当关系词在“主+系+表”结构中做表语，或在“there be”结构中做实义主语时，通常用that，且常省略。
Dr Ham still talks like the man (that) he was ten years ago.
When Lauren was born, Swallow decided her daughter would be the singer (that) she always wanted to be .
The 9:15 is the fastest train (that) there has ever been.
5.如果有两个或两个以上先行词，兼指人或物，应用that;
The famous writer and his works that the radio broadcast have aroused great interest among the students.
They spoke highly of the diplomat and his brilliant success that they read about in the newspaper.
He was watching the children and the parcels that filled the car.
A victim is a person,animal or thing that suffers pain,death,harm,ect.
6.又是为了明确所指的对象避免发生歧义，有时必须用who/whom指人，用which指物，若用that则不恰当。如，
There's only one student in the school (that) I wanted to see.(歧义句)
There's only one student in the school (who) I wanted to see.
5.在非限制性定语从句中，不能用that,做宾语的代词也不能省略；
The Heavenly Lake, which is one of the world famous scenic spots, is on Tienshan Mountain.
天池是世界名胜之一，位于天山之上。
There are thirty students in the class，the majority of whom are from the city.
这个班上有30位学生，大多数来自城市。
6.如果作先行词的集体名词着眼于集体的整体，关系代词用which;如果指集体中的各个成员，则用who;
The basketball team, which is playing very well, will come out first.
The basket ball team, who are having a rest, will begin another match in twenty minutes.
8.在“It is + 名词 + 定语从句 + 定语从句”结构中，后一个定语从句要用that；
It is only a man who has seen much of the world that can be a leader.
只有阅历丰富的人才能当领导。
It is always the mouth which talks too much that arouses troubles.言多必失。
It is a man who is honest that can do the work.只有诚实的人才能做这项工作。
2.作直接宾语的关系代词可以省略；
3.定语从句中关系代词的单复数取决于先行词的单复数；
4.that仅用于限制性定语从句中；而who whom whose which即可用于限制性定语从句中，也可用于非限制
e.g
1.He's the man who/that lives next door to us.
2.Where is the man (whom/who/that) I saw this morning ?
3.Do you know anyone whose family is in xi'an ?
4.James is a man for whom I have the greatest respect .
For mor examples:
使用要点：
1.先行词本身是all,much,everything,something,nothing,anything,little,none等指物的不定代词时关系代词一般只用that，不用which；
Anything that can burn is a source of heat energy.
That's all (that) I could do at that time.
There is little that can be believed about it.
She has nothing that is good to say.
The book doesn't say much that amuses children.
She hates everything that is modern.
2.如果先行词是anyone, anybody, everyone, everybody, someone, somebody, nobody, no one,应用who或whom，不用which；
Is there anyone here who can speak English?
I saw the manager talking with somebody whom he didn't know.
3.先行词被序数词、形容词最高级，以及first,the last,the only,any,few,much,no,some,every等修饰时关系代词常用that，不用which/who/whom；
This is the most impressive TV theater that has never been put on show before.
He is the only person that was present at the time.
This is the best TV set that is made in China.
No sample that we have received is satisfactory.
Please send us any information that you have about the subject.
4.当关系词在“主+系+表”结构中做表语，或在“there be”结构中做实义主语时，通常用that，且常省略。
Dr Ham still talks like the man (that) he was ten years ago.
When Lauren was born, Swallow decided her daughter would be the singer (that) she always wanted to be .
The 9:15 is the fastest train (that) there has ever been.
5.如果有两个或两个以上先行词，兼指人或物，应用that;
The famous writer and his works that the radio broadcast have aroused great interest among the students.
They spoke highly of the diplomat and his brilliant success that they read about in the newspaper.
He was watching the children and the parcels that filled the car.
A victim is a person,animal or thing that suffers pain,death,harm,ect.
6.又是为了明确所指的对象避免发生歧义，有时必须用who/whom指人，用which指物，若用that则不恰当。如，
There's only one student in the school (that) I wanted to see.(歧义句)
There's only one student in the school (who) I wanted to see.
5.在非限制性定语从句中，不能用that,做宾语的代词也不能省略；
The Heavenly Lake, which is one of the world famous scenic spots, is on Tienshan Mountain.
天池是世界名胜之一，位于天山之上。
There are thirty students in the class，the majority of whom are from the city.
这个班上有30位学生，大多数来自城市。
6.如果作先行词的集体名词着眼于集体的整体，关系代词用which;如果指集体中的各个成员，则用who;
The basketball team, which is playing very well, will come out first.
The basket ball team, who are having a rest, will begin another match in twenty minutes.
8.在“It is + 名词 + 定语从句 + 定语从句”结构中，后一个定语从句要用that；
It is only a man who has seen much of the world that can be a leader.
只有阅历丰富的人才能当领导。
It is always the mouth which talks too much that arouses troubles.言多必失。
It is a man who is honest that can do the work.只有诚实的人才能做这项工作。