Question

定语从句中，what与which区别，分别举例。谢谢了。(尽量通俗些)

Answer 1

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.

Answer 2

首先定语从句的连接词不可以用what．
一.定语从句及相关术语
1.定语从句：修饰一个名词或代词的从句称为定语从句，一般紧跟在它所修饰的先行词后面。
2.关系词：引导定语从句的关联词成为关系词
关系词有关系代词和关系副词。关系代词有that, which, who, whom, whose, as 等；
关系副词有where, when, why等。
关系词常有3个作用：1，引导定语从句。2，代替先行词。3，在定语从句中担当一个成分。
用which的情况
a) 在引导非限定性定语从句时。

The tree, which is four hundred years old, is very famous here.

b) 介词后不能用。

We depend on the land from which we get our food.
We depend on the land that/which we get our food from.
2) 只能用that作为定语从句的关系代词的情况
a) 在there be 句型中，只用that，不用which。

b) 在不定代词，如：anything, nothing, the one, all, much, few, any, little等作先行词时，只用that，不用which。
c) 先行词有the only, the very修饰时，只用that。
d) 先行词为序数词、数词、形容词最高级时，只用that。.
e) 先行词既有人，又有物时。
举例：
All that is needed is a supply of oil.
所需的只是供油问题。

Answer 3

what 相当于“先行词+关系代词”，如 This is what he said (=the words that he said)，属于关系代词性连接词，本身不能引导定语从句。which 则是关系代词，用来指代表示事物的先行名词。