Question

定语从句中的连词what和which有什么区别

Answer 1

定语从句：指人时常用which 和 who 而 what 则常用于指物

名词性从句分为：主语从句,宾语从句,同位语从句和表语从句.

what可以引导名词性从句,在从句中可做主语、宾语、表语.

which是关系代词,引导定语从句,在从句中可充当主语、宾语、表语.引导定语从句的词分为关系代词（which,that,who,whom,whose,as）关系副词（when,where,why）,注意：没有what.

如：

1.This is the book which I talked about yeasterday.

(which引导定语从句放在名词book后面起修饰作用,which在从句中充当talk about的宾语)

2.This book is what I talked about yesterday.(what引导名词性从句,放在is之后,what 在表语从句（名词性从句）充当talked about的宾语.)

1. that可以指人,也可以指物；which只能指物

   2.当先行词是不定代词all,something,anything,everything,none,the one等时,只能用that

3.先行词前有形容词的最高修饰时,要用that

4.先行词前有序数词修饰时,要用that

5.先行词前有形容词only,very,few,little等修饰时,要用that

6.先行词既指人,又指物时,只能用that
7.在非限制性定语从句中,只能用which

8.在介词+关系代词引导的定语从句中,必须用which

9.当先行词本身是that的时候,要用which

Answer 2

注意：what不可以用在定语从句中。
定语从句的关系代词that的用法:若先行词指人或物则代替先行词在定语从句中充当主语或宾语

Theanimalthat\whichislostisapanda.

先行词指物代替先行词在定语从句中充当主语

Sheisthepersonthat\whoweareworriedabout.

先行词指人代替先行词在定语从句中充当宾语

which引导的定语从句的用法
which可以引导定语从句，修饰表示事物的先行词，在定语从句中充当主语、宾语或者表语。例如：Hewasreadingabook，whichwasaboutwar.他正在读一本关于战争的书。（关系代词which在修饰book的定语从句中充当主语。）
Hewasreadingabook，whichhehadboughtfromLondon.他正在读一本书，这本书是从伦敦买回来的。（关系代词which在修饰book的定语从句中充当宾语。）
which引导非限定性定语从句时有一个特殊用法，即它所引导的非限定性定语从句修饰主句中更多的部分甚至整个主句（这时被定语从句所修饰的“先行词”要作广义理解），which仍在定语从句中作主语、宾语或表语。例如：
Hesetfreethebirdshappily，whichwasacelebrationforhissuccess.他开心地把鸟放了，这是对他成功的一种庆祝。
把非限定性定语从句“whichwasacelebrationforhissuccess”的先行词视为主句中的“thebirds”显然不符合整句的语境，被“whichwasacelebrationforhissuccess”所修饰的是整个主句，which所引导的这类特殊的非限定性定语从句对主句所叙述的情况进行某种意义的补充说明，which常可译为“这一点，这件事”

Answer 3

定语从句不用what引导,名词性从句用what引导
定语从句缺主语或宾语用which（先行词为物）
名词性从句缺主语或宾语用what

定语从句中一般不用what.that和which的区别在于：
1.that可以指人,也可以指物；which只能指物
2.当先行词是不定代词all,something,anything,everything,none,the one等时,只能用that
如：Is there anything that I can do for you?
3.先行词前有形容词的最高修饰时,要用that
如：This is the best film that I have ever seen for years.
4.先行词前有序数词修饰时,要用that
如：This is the fifth book that I have ever written.
5.先行词前有形容词only,very,few,little等修饰时,要用that
如：She was the only person that was invited to the palace.
6.先行词既指人,又指物时,只能用that
7.在非限制性定语从句中,只能用which
如：She made great progress and won a prize,which gave us a surprise.
8.在介词+关系代词引导的定语从句中,必须用which
如：This is the knife with which John hurt somebody.
9.当先行词本身是that的时候,要用which
如：The predicate is that which is said of the subject.