一．什么叫定语从句？

一个句子作定语就叫定语从句。

二．定语从句的结构及种类

1. 结构：关系词+主语+谓语+其它

2. 种类：限制性定语从句和非限制性定语从句

三．关系词的分类及关系词

1. 关系代词：who，whom, whose, that ,which, as

2. 关系副词：when，where，why

四．关系词的功用

1. 起连接作用，引导定语从句

2. 在定语从句中作一个成分——主语，宾语，状语，定语，表语。

五．什么是先行词？

被定语从句所修饰的词是先行词。

六．关系词的用法

1. who

当先行词是指人得名词或代词，而且关系词在句中作主语时，选who。

The boy who is standing over there is Tom.

He who doesn’t reach the Great Wall is not a true man.

2. whom

当先行词是指人得名词，而且关系词在句中作主语时，选whom.

This is our English teacher whom everybody likes.

3. whose

① 当先行词是指人的名词，而且关系词在句中作定语时，选whose.

This is my deskmate whose father works in a factory.

② 当先行词是指物的名词，而且关系在句中作定语时，选whose.

We study in a classroom whose windows face to the south.

4. that

① 当先行词是指物的名词，关系词在句中作主语时，选that.

This is a machine that can walk.

② 当先行词是指物的名词，关系词在句中作宾语时，选that. 另外，that可以省略。

I like the present (that) my father sent me.

③ 当先行词是指人的名词，关系词也可选用that=who

The boy that/who is playing football on the play ground is my brother.

5. which

当先行词是指物的名词时，关系词也可选用which，它在句中作主语或宾语，which=that

6. 下列情况下，关系词只能选用that

① 当先行词为不定代词 something, anything, nothing, everything时

Is there anything that I can do for you?

② 当先行词为不定代词all时

Mr. Li does all that he can to do his work well.

③ 当先行词被all, some, any修饰时

These are all the things that I have done today.

④ 当先行词被the only, the very 修饰时

This is the only computer that he often turns to for help.

⑤ 当先行词被序数词，形容词最高级修饰时

This is the cleaning room that you can see here.

⑥ time 作先行词，前面有序数词或last修饰时

This is the last time that I’ll give you pocket money.

⑦ 尽管先行词指人，但关系词在句中作表语时。

He is no longer the child that he used to be 20 years ago

⑧ 以 who开头的特殊疑问句，尽管先行词指人。

Who is the person that is sitting on the ground ?

⑨ 当先行词包括人和物时。

7. 下列情况下，关系词只能选which

① 在非限制性定语从句中。

This is my favorite pen, which I bought yesterday.

② 先行词不是一个词，而是前面整个句子的概念时

The boy is very polite, which makes his parents happy.

③ 当先行词指物，用“介词+which”

This is the pen with which I often write.

8. as

As 引导定语从句时，有四种情况。As在句中作主语，宾语。

① as 单独引导定语从句。

As we all know (=As is known to us all), Yao Ming is a famous basketball player.

② the same …as… 与…一样

I have the same idea as you.

③ such… as… 和…一样

Don’t read such a book as you can’t understand.

④ as…as… 和…一样

In this library, you can borrow as many books as you can.

9. where

① 当先行词是指地点的名词，而且关系副词在句中作状语时，选where，where=介词+which

This is the classroom where we study.

② 尽管先行词是指地点的名词，但关系词在句中作主语，宾语时，只能选that/which.

This is the factory that/which makes paper

This is the factory(that/which) we visited yesterday.

③ 尽管先行词是指地点的名词，关系词在句中作主语，宾语，但非限制性定语从句只能用which

This is the school, which he visited.

④ the one 是代词，代替前面的名词，其后的that/which 往往省略。

Is this factory the one you visited?

⑤ 当situation, job, mark, race, point 等模糊概念的名词，关系词在句中作状语时，选where

You’d better make a mark where you have any questions.

⑥ 尽管先行词是指地点的名词，关系词在句中作状语，但定语从句末有介词时，选which。

This is the lab which we do experiments in.

10. when

① 当先行词是指时间的名词，而且关系副词在句中作状语时，选when，when=介词+which

We will never forget the days when we stayed with Mr. Smith.

② 尽管先行词是指时间的名词，但关系词在句中作主语，宾语时，选that或which。

Monday is the day which/that comes before Tuesday.

We will never forget the days (that/which) we spent with him.

③ 尽管先行词是指时间的名词，关系词在句中作主语，宾语，但非限制性定语从句只能选which。

Wednesday is the day, which comes before Thursday.

④ one 作替代词，代替前面表示时间的名词，其后的that/which往往省略。

That was an exciting moment, one I will remember forever.

⑤ time作先行词，前面有序数词或last时，只能选that。

Is this the third time that you have been late for school this week?

11. why

① 当先行词是指表示原因的名词reason时，如果关系副词作状语，选why，why=for which.

This is the reason why I didn’t attend the meeting yesterday.

② 当先行词是表示原因的名词reason时，如果关系副词在句中作宾语，选that/which,也可省略。

My parents didn’t believe the reason (that/ which) I give him.

七．介词+which/whom

1. 介词+which/whom

① 介词的选择根据下面四种情况

a. 根据定语从句中的谓语动词

Who is the person with whom you shook hands just now?

b. 根据定语从句中的形容词

In learning English, he had two things about which he was not sure.

c. 根据定语从句所修饰的先行词

This is the bike by which I go to school.

d. 根据句意。

This is the train on which he works.

② 如果关系词指人，选whom，如果关系词指物，选which。

2. 不定代词+of+which/whom

常用的不定代词有：both, neither, either(两者之一)，all, none, many, most, some, any

Mr. Li has two sons, both of whom are college students.

There are 10.000 books in this library, most of which are interesting.

3. 数词，分词，百分数+of+which/whom

There are 50 students in our class, two thirds of whom are girls.

4. the+名词+of+which=whose+名词

He has just bought a magazine, the cover of which (=whose cover) is missing.

5. 介词+whose+名词

This is our school teaching building, on whose top there is a red flag.

八．非限制性定语从句

如果主语和定语从句之间有个逗号，它就是非限制性定语从句。引导非限制性的定语从句的关系词有：which，who, when, where, why, whom, whose.

九．分隔性的定语从句

有时定语从句和先行词之间被其他词隔开，把这种从句叫分隔性的定语从句。

The days are gone when China used foreign oil.

= Gone are the days when China used foreign oil.

十．The way 作先行词，引导定语从句的关系词有三种情况：that, in which 省略。

I don’t like the way ___D___ you do things.

A. that B. in which C. × D. all of the above

十一. One of +the+复数名词+定语从句，谓语动词用复数，the only one of +the 复数名词+定语从句，谓语动词用单数。

He is one of the teachers in our school who teach well.

He is the only one of the teachers in our school who teaches well.

十二. 在定语从句中，谓语动词的单数，复数依据它所修饰的先行词。

I, who am your teacher, will help you with everything.

He who breaks the school rules should be punished.

Those who break the school rules should be punished.

Anyone who breaks the school rules should be punished.

十三. 定语从句和并列句的区别

非限制性的定语从句和主语之间有一个逗号，并列句的结构式单句+并列连词（and, or. so, but）+简单句.

I have many friends, all of whom are kind to me.

I have many friends and all of them are kind to me.