定语从句引导词that和which的区别

that既可指人又可指物,而which则一般指物.区别如下：
一、以下情况不能用that,只能用which：

1、在非限定性定语从句中,逗号之后不能用that；
2、介词后面不能用that.
3、当主句中的主语被that修饰时。That cat which I found in the street belongs to Jane.

二、以下情况不能用which,只能用that：

1、前面的先行词是不定代词时,如 all ,anything ,nothing,the one 等；
2、如果先行词出现了the only ,the very 时；This is the very book that I lost yesterday.
3、如果先行词出现了序数词和形容词最高级时；
4、如果先行词中既有人又有物时,如：They are talking about the school and the teachers that they visited yesterday.
5、在there be句型中,只用that
6、如有两个定语从句,其中一个已用which引导,另一个宜用that .Johnson built up a factory which produced things that had never been seen before.
7、主句是以which或who开头的特殊疑问句时Who is the woman that was praised at the meeting.
8、当先行词在从句和主句中都作表语时,无论先行词是人还是物。
9、当先行词被all, any, some, no, not, every, each等修饰时。

首先,that可指人和物,which则一般指物.,在限定性定语从句中两者的区别不大,但在非限定性定语从句中有以下区别：
一、以下情况不能用that,只能用which：1、在非限定性定语从句中,逗号之后不能用that；2、介词后面不能用that.
二、以下情况不能用which,只能用that：
1、前面的先行词是不定代词时,如 all ,anything ,nothing,the one 等；
2、如果先行词出现了the only ,the very 时；
3、如果先行词出现了序数词和形容词最高级时；
4、如果先行词中既有人又有物时,如：They are talking about the school and the teachers that they visited yesterday.

that与which的用法区别

两者都可指物，常可互换。其区别主要在于：
1. 引导非限制性定语从句时，通常要用which：
The current, which is very rapid, makes the river dangerous.
水流湍急，使这条河很危险。
He has to work on Sundays, which he doesn’t like.
他得在星期天工作，他是不喜欢这样的。
The London team, which played so well last season, has done badly this
season.
伦敦队上一个季度打得很好，这个季度却打得很差。
2. 直接放在介词后作宾语时，通常要用which：
She may be late, in which case we ought to wait for her.
她可能晚到，那样我们就要等等她。
The documents for which they were searching have been recovered.
他们找寻的文件已找到了。
This morning some port wine came, for which I have to thank you.
今天早上送来一些波尔图葡萄酒，为此我得向你道谢。
注：有时“介词+which”引导的定语从句可以转换成“介词+which+不定式”结构：
He had only the long nights in which he could study. =He had only the long nights in which to
study.
他只有漫漫长夜可用来学习。
He had a couple of revolvers with which he could defend himself.= He had a couple of revolvers with which to defend himself. 他只有一两把手枪用来自卫。
3. 当先行词是下列不定代词或被它们修饰时much, little, none, all,few, every(thing), any(thing), no(thing) 等时，通常用that：
All that she lacked was training.
她缺的只是训练。
Have you everything that you need?
你需要的东西都有了吗?
The sleeping man’s subconscious mind retained everything that was said
around him.
这位酣睡的人头脑的下意识能记住他周围的人说的话。
She would never do anything that was not approved of by her parents.
她父母不赞同的事她绝不会做。
4. 当先行词有
the very, the only, the same 等修饰时，通常用that：
This is the only example that I know.
我知道的例子只有这一个。
Those are the very words that he used.
那是他的原话。
5. 当先行词有形容词最高级或序数词(包括last, next等)等修饰时，通常用that：
This is the best dictionary that I’ve ever used.
这是我用过的最好的词典。
The first thing that you should do is to work out a plan.
你应该做的第一件事是订个计划。
6. 当关系代词在定语从句中用作表语时，通常用that：
China is not the country (that) it was.
中国已不是过去的中国了。
7. 当先行词是一个既指人又指物的并列词组时，通常用that：
They talked about the persons and things that most impressed them.
他们谈论了使他们印象最深的人和事。
8. 当要避免重复时：
Which is the course that we are to take?
我们选哪门课程？

一) 当先行词指物时只能用 that 而不能用which 的几种常见情况
1 先行词为all, anything, everything, nothing, much, none, little 等不定代词时。
如There is nothing that can stop him from doing it
2 先行词前有 last, next, only，very 及序数词、最高级等修饰时。如
This is the most interesting film that was shown last week
这是上周所放映的影片中最有趣的一部。
The only thing that they can do is to wait
他们唯一能做的事就是等待。
3 先行词前有序数词或最高级等修饰时。如
This is the second computer that father has just bought
这是爸爸刚刚买的第二台电脑。
This is the very pen (that) you bought yesterday

这正是你昨天买的笔。
4当先行词既有人，又有物时。如
Sally is talking about the writer and his book that interests her
萨丽在谈论这位作家及能使她感兴趣的这位作家的书。
5 当主语是who 的疑问句。如
Who is the boy that is playing computer games?
在玩电脑游戏的男孩是谁?
二)
当先行词指物时，只能用 which 而不能用that 的场合
1关系代词前有介词时。如
This is the house in which Tom once lived
这是汤姆曾经住过的房子。
2 在非限定性定语从句(即通常用逗号与主句隔开，如果去掉逗号，整个句子仍能表达完整的意义的定语从句)中。如
They are talking about the TV play, which they saw last night

他们正在谈论昨晚看的电视剧。