7. 当先行词指人时that一般可以与who 通用。但是当先行词符合下列条件之一时，只能用who.

⑴ 当先行词是one, ones, anyone, those指代人时， 只能用who.

Anyone who does that must be mad. 谁那样做一定是疯了。

⑵ 在there be 结构中，先行词是人时，只能用who.

There is a girl who is waiting for you. 有个女孩在等你。

⑶ 当先行词是人，后面有较长的修饰语时，只用who.

I met a friend of mine who had got three gold medals in the Asian Games.

昨天我在公园见到一个朋友，他在亚运会上得到了三枚金牌。

⑷ 当先行词是I, you, he ,they等时(常用于谚语中)，只用who.

He who plays with fire gets burned. 玩火自焚。

II. 关系副词

关系副词可代替的先行词是时间、地点或理由的名词，在从句中作状语。常用关系副词有why, when, where.

1. when 指时间，在定语从句中作时间状语。也可以用“介词+关系代词”代替when, 这时的介词一般为in, at, on等。

I'll never forget the day when (on which) I first come here.

我永远都不会忘记我第一次到这儿的那天。

2. where 指地点，在定语从句中作地点状语。也可以用“介词+关系代词”代替where, 这时的介词一般为表示方位的at, in , on, beside等。

This is the room where (in which) he lived last year. 这是他去年住过的房间。

3. why指原因，在定语从句中作原因状语。也可以用“介词+关系代词”代替why, 这时的介词一般为for。

That’s the reason why (for which) he was late for school. 这就是他上学迟到的原因。

4. that 可用于表示时间、地点、方式、理由的名词后取代when, where, why引导的定语从句，在口语中that常被省略。

This is the place (that / where / in which) he works. 这是他工作的地方。

非限制性定语从句

关系代词和关系副词在非限制性定语从句中的应用与在限制性定语从句中类似。先行词为人时，用who, whom, whose;先行词为物时，用which。 that不用于非限制性定语从句中。

Mary has a brother, who is an engineer. 玛丽有一个兄弟，他是一位工程师。

She has six cousins, three of whom lived to grow up.

她有六个表兄弟，其中三个已经长大成人了。

The children are taught by a 32-year-old Englishman, whose wife is an American.

孩子们的老师是一位32岁的英国人，他的妻子是美国人。

非限制性定语从句也可以由where或when 引起。

Last week we visited Hangzhou, where there is a beautiful lake.

上周我们游览了杭州，那儿有一个美丽的湖。

We will put off the party until next week, when we won't be so busy.

我们把晚会推迟到下周，那时我们就不会这么忙了。

定语从句专练

单项选择. 从题后所给四个选项中选择最佳答案填入空白处。

1. Mr. Li is an English teacher ______ loved playing soccer.

A. who    B. whom    C. he    D. which

2.  We called the man ________ had promised to help us.

A. he     B. that    C. whom    D. which

3.  The coat _______ he is wearing today was bought by his aunt.

A. what    B. where    C. who      D. that

4.  The place _______ he works is in the factory.

A. that    B. which    C. in which   D. in where

5.  That's the most beautiful place ______ I have ever __________.

A. where; visited  B. that; visit   C. where; visit   D. that; visited

6.  I don't know the boy ________________.

A. whom you often talk    B. you often talk with

C. with who you often talk   D. that you often talk

7.  Look! The boy ______ name is Simon is playing soccer with his friends.

A. who    B. whose    C. which    D. whom

8.  All ______ they have done is good for us.

A. what    B. which    C. why    D. that

9.  I want to go to some places ________ it's cool in summer.

A. those    B. which    C. where    D. this

10. Saturday is the day _______ people can have a rest.

A. that    B. at which   C. on which   D. on that

11. She is new here, there are no friends ______ she can ______ turn for help in the city.

A. whom    B. to whom   C. which    D. to which

12. He is one of the boys ________ basketball well.

A. whom play   B. whom plays  C. who play   D. who plays

13. The fence in our garden, _______ my father built many years ago, has lasted for a long time.

A. that    B. which    C. what    D. where

14. I'll remember the time ______ we spent together in the country.

A. that    B. when    C. during which  D. at which

15. I don’t believe the reason _______ he has given for his being late.

A. why    B. that    C. how    D. what

16. There are two caps on the table, _______ belongs to Tom.

A. the smaller of which B. the small of which C. the smaller of them D. the small one

17. My brother had become a doctor, ______ was what he wanted to be.

A. who    B. what    C. that    D. which

18. There is a mountain _______ the top is always covered with snow.

A. whose    B. of which   C. it's    D. that

19. Is there a post office around ______ I can get some stamps?

A. which    B. what    C. where    D. that

20. He talked happily about the man and books _______ interested him greatly in the school.

A. which    B. that    C. who    D. when

21. There isn't a dictionary _______ you can find everything.

A. that    B. which    C. where    D. in that