定语从句只用who不能用that的情况

如果先行词是those,they,all,persons,people,he,anyone,one时用who不用that.在定语从句中who和which都是关系代词，都在句中作主语，that除作主语以外还可以作宾语，指代人或物，而who只能指人。下面具体来看看只用who不用that的情形。

定语从句只用who不能用that的情况

1、先行词为people、those、one、ones、anyone、everyone、none、all等指人的代词时。例如：

Success will belong to those who never say "impossible".

成功将属于那些从不说“不可能”的人。

2、主句为there be结构且先行词为人时。例如：

There was once a wise old man who lived on a hill.

从前山上住着一位聪明的老人。

3、先行词为人，且关系词与先行词之间存在其他成分时。例如：

He did his best to help others in the company who were deaf or blind.

他尽力帮助公司里耳聋或眼瞎的人。

4、引导非限制性定语从句，且先行词为人时。例如：

Tom, who had stolen the book, realized his mistake.

汤姆偷了这本书，他已经意识到了这个错误。

5、前面已经有一个that引导的定语从句时。例如：

The girl that you met just now is my sister who just graduated from Beijing University.

刚才你见到的那个女孩是我刚从北京大学毕业的姐姐。

定语从句宜用which不用that的情况

1、先行词是指物的名词且关系代词前有介词时。例如：

I'll never forget the town in which there used to be a clean river.

我永远不会忘记那个曾经有一条清澈小河的小镇。

2、先行词本身就是that，且指代的是物时。例如：

What's that which flashed in the sky just now?

刚才在天空中闪烁的是什么？

3、引导非限制性定语从句，且先行词为物时。例如：

I borrowed the book from the library last week, which my classmates recommended to me.

上个星期我从图书馆借来了这本书，它是我的同学推荐给我的。

4、先行词后面有插入语时。例如：

Here is the CD which, as I have told you, is a great help to you.

这就是那张我说过对你很有帮助的光盘。

who和which的用法区别

1、which一般指代事物、动物，或者指代婴儿、小孩；who指代人或者拟人化的动物。which 表明先行词是物（也指事）在限定性定语从句中=that，在非限定性定语从句中只能which，不能用who。

The book which I bought is very cheap. 

我买的书非常便宜。 　　

I know the man who stole Mary's wallet. 

我认识偷玛丽钱包的人。 　　

Which period of history would you most like to have lived in? 

你最喜欢生活在哪一个历史时期？

2、who 表明先行词是人（一般在从句中充当主语），which 表明先行词是物（也指事）在限定性定语从句中=that，在非限定性定语从句中只能which 。 　　

The boy who plays computer well is waitting for you. 

那个电脑玩得很好的男孩正在等你。

This is the hotel which you will stay in. 

这就是你将要住的旅馆。　

Tom is late for class, which makes his mum very angry. 

汤姆上课迟到了，这使他妈妈很生气。

Beijing, which ia the capital of China, is a beautiful city. 

北京是中国的首都，是一座美丽的城市。