1.人

who(主语、宾语)

whom(宾语)

that(主语、宾语)

The man who/that   is speaking at the meeting is a famous scientist.（作is speaking的主语）

在会上讲话的人是一位著名的科学家。

He who/that   does not reach the Great Wall is not a true man.（作does not reach的主语）

不到长城非好汉。

This is the   famous scientist (who/whom/that) we visited last week.（作visited的宾语）

这就是我们上周拜访的那位著名科学家。

2.物

that(主语、宾语)

which(主语、宾语)

He finally   worked out the problem which/ that puzzled him for a long time.（作puzzled的主语）

他最后解出了这个令他困惑很久的问题。

The fish (that/which)   we bought yesterday were not fresh. （作bought的宾语）

我们昨天买的鱼不新鲜。

3.人的；

物的

whose(定语)

They rushed   over to help the man whose car broke down. （whose car=the   man’s car，作定语，修饰car）

他们跑过去帮助那个汽车抛锚的人。

There is a   mountain whose top is always covered with snow.( whose top=the   mountain’s top，作定语，修饰top)

有一座山顶常年被雪覆盖的山。

4.句子

（在非限制性定语从句中）

which(主语、宾语)

as(主语、宾语)

The weather   turned out very good, which was more than we could expect.（which指代“天气最后晴朗起来”，作was的主语）

天气最后晴朗起来，这是我们没有料到的。

As everyone   knows,   China is a beautiful country with a long history.（As指代“中国是一个有着悠久历史的美丽国家”，作knows的宾语）

每个人都知道，中国是一个有着悠久历史的美丽国家。

2.从句中代词的重复多余

定语从句中的引导词指代先行词，并在从句中作成分，从句中不能再出现指代该先行词的代词。

The book   that I read it yesterday is very interesting.（×）

The book   that I read yesterday is very interesting.（√）

我昨天读的那本书很有趣。

This is the   woman who I met her last time.（×）

This is the   woman who I met last time.（√）

这就是我上次遇见的妇女。

3.关系代词和代词的误用

定语从句的引导词要用关系代词，而不能用一般代词。

This is the   boy he told me a story yesterday.（×）

This is the   boy who told me a story yesterday.（√）

这就是昨天给我讲故事的男孩。

This is the   boy his father is our headmaster.（×）

This is the   boy whose father is our headmaster.（√）

这就是这个男孩，他的爸爸是我们的校长。

4.what不引导定语从句

定语从句中有关系代词that和which ，而没有what ，what 可以引导名词性从句。

All that we   need is a supply of oil. (that引导定语从句，修饰先行词all)

What we need is   a supply of oil. (what引导主语从句)

我们需要的是石油供应。

5.that不引导非限制性定语从句（用逗号隔开）

在非限制性定语从句，不能用关系代词that。如果指代“人”，用关系代词who/ whom，指代“物”，用关系代词which。

The basketball   star, who tried to make a comeback, attracted lots of attention. 这位打算复出的篮球明星引起了很多关注。

Beijing, which   is the capital of China, is a beautiful city. 中国的首都北京是座美丽的城市。

He has become   a doctor, which he wanted to be.

他成为了一名医生，这是他以前一直梦想的。

6.介词+which/whom

先行词在从句中作介词宾语，若介词提前，指代物时，只能用which，不用that；指代人时，只能用whom，而不用who。介词不提前时，用that/which, who   /whom都可以。

I have the   book about which you are talking.

= I have the   book (that/ which) you are talking about.

我有你现在谈论的那本书。

The man with   whom I talked just now is from Beijing University.

= The man (who/   whom/ that) I talked with just now is from Beijing University.

刚才和我谈话的那个人是从北京大学来的。

7.whose+n.

= the+n

+of which

=of which

+the+n.

whose+n.可与the+n +of   which

互换，而且of which也可置于名词之前，名词之前必须有定冠词the。

I live in the   room whose window faces south.( whose window=the room’s window)

I live in the   room the window of which / of which the window faces south.( the   window of which= the window of the room)

我住在窗子朝南开的房间里。

8. 定语从句中的主谓一致：

关系代词在定语从句中做主语时，定语从句的谓语通常与先行词在人称和数上保持一致。

注意：当先行词为“one of +复数名词”时定语从句的谓语动词用复数形式；当先行词为“the   (only/very)one of +复数名词”时定语从句的谓语动词用单数形式。

He is a good   student who likes to help others.

他是一个乐于助人的好学生。

They are good   students who like to help others.

他们是乐于助人的好学生。

He is one of   the students who were praised.

他是一个受到表扬的学生之一。

He is the one/   the only one of the students who was praised.他是唯一一个受到表扬的学生。

②当先行词被the only, the very, the same等词修饰时。

That’s the   only thing that we can do now.目前我们只能这样了。

This is the   very pen that I am looking for.这正是我找的钢笔。

He still lives   in the same house that we visited ten years ago.他还住在十年前我们参观的同一座房子里。

③当先行词被序数词、形容词最高级修饰时。

This was one   of the most interesting books that were sold in this book store.

这是这家书店售出的最有趣的书之一。

The first   thing that should be done is to get some food.该做的第一件事是弄点吃的。

④当先行词中同时包括人和物时。

I’m going to   talk about the countries and people that I have visited.

我要谈论一下我所访问的国家和人民。

⑤当要避免与疑问词which重复时。

Which is the   T-shirt that fits me most?

那件体恤衫最适合我？

2.用which，不用that的情况

①在非限制性定语从句中

Football, which   is an interesting game, is played all over the world.

全世界都踢足球，它是一项有趣的运动。

②介词提前时，不用that，而用which，介词不提前时，用that和which都可。

This is the   room in which my father lived last year.

=This is the   room (that/ which) my father lived in last year.

这是我父亲去年居住过的房子。

2.语义的区别：

as有“正如”之意，因此主句和从句语义一致，而which表示“这一点” 在意义上相当于一个并列句，可以用and   this代替，在语义上可以不一致。

Mike won the   first prize, as was expected.

正如所料想的, 迈克获得了一等奖。

Mike won the   first prize, which was not expected.

迈克获得了一等奖，这一点没被料想到。

2. 在非限制性定语从句中，指代整个主句内容。

As we know,   she is a good teacher.

我们都知道她是一个好老师。

Lily, as we   expected, won the first prize in the competition yesterday.

像我们所期望的那样，莉莉在昨天的比赛中获得了一等奖。