高考英语三大从句(名词性从句、定语从句、状语从句)讲解+练习(附答案)

高考英语三大从句讲解+练习（附答案）
【名词性从句】
名词性从句相当于名词，可分别作主句的主语、表语、宾语和同位语。

因此，名词性从句成分为主语从句、表语从句、宾语从句和同位从句。

（一）引导名词性从句的连接词
1、连接代词：who, whose, whom, what, which。

有词义，在从句中担任成分，如主语、表语、宾语、或定语等。

2、连接副词：when, where, why, how。

有词义，在从句中担任成分，作状语。

3、连接词：that, whether, if, as if。

that 无词义，在从句中不担任成分，有时可省略；if (whether), as if虽有词义，但在从句中不担任成分。

1. 主语从句
作句子主语的从句叫主语从句。

主语从句通常由从属连词that，whether，if和连接代词what，who，which，whatever，whoever以及连接副词how，when，where，why等词引导。

that在句中无词义，只起连接作用；连接代词和连接副词在句中既保留自己的疑问含义、又起连接作用，在从句中充当从句的成分。

例如：
What he wants to tell us is not clear. 他要跟我们说什么，还不清楚。

It is known to us how he became a writer. 我们都知道他是如何成为一名作家的。

Where the English evening will be held has not yet been announced.
英语晚会将在哪里举行，还没有宣布。

有时为避免句子头重脚轻，常用形式主语it代替主语从句作形式主语放于句首，而把主语从句置于句末。

主语从句后的谓语动词一般用单数形式。

常用句型如下：
（1）It + be + 名词+ that从句（2）It + be + 形容词+ that从句
（3）It + be + 动词的过去分词+ that从句（4）It + 不及物动词+ that 从句
另注意在主语从句中用来表示惊奇、不相信、惋惜、理应如此等语气时，谓语动词要用虚拟语气“(should) +do”，常用的句型有：
It is necessary (important, natural, strange, etc.) that …
It is a pity (a shame, no wonder, etc.) that…
It is suggested (requested, proposed, desired, etc.) that…
注意：连词that, whether在从句中不担任句子成分，只起连接作用，不能省略。

并且whether引导主语从句时不能用if
代替。

Whether there is life on the moon is an interesting question. 月球上有没有生命是个有趣的问题。

注意：who, which, how, when, where, why在所引导的主语从句中可担任主语，宾语，状语，不能省略。

可以用形式主语it引导。

2. 宾语从句
名词句用作宾语的从句叫宾语从句。

引导宾语从句的关联词与引导主语从句表语从句的关联词大致一样，在句中可以作谓语动词或介词及非谓语动词的宾语。

1. 由连接词that引导的宾语从句
由连接词that引导宾语从句时，that在句中不担任任何成分，在口语或非正式的文体中常被省去，但如从句是并列句时,第二个分句前的that不可省。

例如：
He has told me that he will go to Shanghai tomorrow. 他已经告诉我他明天要去上海。

We must never think (that) we are good in everything while others are good in nothing.
我们决不能认为自己什么都好，别人什么都不好。

注意：在demand、order、suggest、decide、insist, desire, request, command等表示要求、命令、建议、决定等意义的动词后，宾语从句常用“（should）+ 动词原形”。

例如：
I insist that she (should) do her work alone. 我坚持要她自己工作。

The commander ordered that troops (should) set off at once. 司令员命令部队马上出发。

2. 用who，whom, which, whose, what, when, where, why, how, whoever, whatever, whichever等关联词引导的宾语从句相当于特殊疑问句，应注意句子语序要用陈述语序。

例如：I want to know what he has told you. 我想知道他告诉了你什么。

She always thinks of how she can work well. 她总是在想怎样能把工作做好。

She will give whoever needs help a warm support. 凡需要帮助的人，她都会给予热情的支持。

3. 用whether或if引导的宾语从句，其主语和谓语的顺序也不能颠倒，仍保持陈述句语序。

此外，whether与if 在作“是否”的意思讲时在下列情况下一般只能用whether，不用if：
a. 引导主语从句并在句首时；
b. 引导表语从句时；c . 引导从句作介词宾语时；d. 从句后有“or not”时；e. 后接动词不定式时。

例如：Whether there is life on the moon is an interesting question.
月球上有没有生命是个有趣的问题。

Everything depends on whether we have enough money. 一切要看我们是否有足够的钱。

4. 注意宾语从句中的时态呼应，当主句动词是现在时，从句根据自身的句子情况，而使用
不同时态。

例如：he studies English every day. （从句用一般现在时）
he studied English last term. （从句用一般过去时）
I know (that) he will study English next year. （从句用一般将来时）
he has studied English since 1998. （从句用现在完成时）
当主句动词是过去时态（could, would除外），从句则要用相应的过去时态，如一般过去时，过去进行时，过去将来时等；当从句表示的是客观真理，科学原理，自然现象，则从句仍用现在时态。

例如：The teacher told us that Tom had left us for America．
3. 表语从句
在句中作表语的从句叫表语从句。

引导表语从句的关联词与引导主语从句的关联词大致一样，表语从句位于连系动词后，有时用as if引导。

其基本结构为：主语+ 系动词+ that从句。

例如：
The fact is that we have lost the game. 事实是我们已经输了这场比赛。

That is why he didn’t come to the meeting. 那就是他为什么不到会的原因。

It looks as if it is going to rain. 看上去天要下雨了。

需要注意的，当主语是reason时，表语从句要用that引导而不是because。

例如：
The reason why he was late was that he missed the train by one minute this morning
4. 同位语从句
同位语从句说明其前面的名词的具体内容。

同位语从句通常由that引导，可用于同位语从句的名词有advice、demand、doubt、fact、hope、idea、information、message、news、order、problem、promise、question、request、suggestion、truth、wish、word等。

例如：
The news that we won the game is exciting.我们赢得这场比赛的消息令人激动。

I have no idea when he will come back home. 我不知道他什么时候回来。

The thought came to him that Mary had probably fallen ill. 他想到可能玛丽生病了。

同位语从句和定语从句的区别：
that作为关系代词，可以引导定语从句，充当句子成分，在从句中作宾语时可以省略；that引导同位语从句时，起连词的作用，没有实际意义，不充当句子成分，一般不能省略。

试比较下面两个例句:
I had no idea that you were here．（that引导同位语从句，不能省略）
Have you got the idea（that）this book gives you of life in ancient Greece？（that引导定语从句，作宾语，可以省略）
5.疑问词+ever和no matter+疑问词的区别。

① 疑问词+ever可引导名词性从句，在主从句中要充当一定的部分。

如：
Whoever breaks the rule must be punished.
You can choose whatever you like in the shop.
① 疑问词+ever还可引导让步状语从句。

如：
Whoever breaks the rule,he must be punished,
Whatever you do,you must do it well.
① no matter+疑问词只能引导让步状语从句。

如：
No matter what you do,you must do it well.
No matter who breaks the rule,he must be punished.
6.名词性从句中主句和从句的时态一致
（1）宾语从句中主句和从句的时态保持一致，但如果从句中表示提示的是客观现象，虽然主句是过去时态，从句仍用一般现在时。

如：
Hello,I didn’t know you were in London.How long have you been here?
The teacher told us that light travels at a very high speed.
（2）主语从句作主语相当于单数第三人称作主语，谓语动词用单数，如果由and连接两个或两个以上的主语从句作主语时，谓语动词用复数；由两个或多个连接词引导一个主语从句，谓语动词用单数。

如：
When the meeting will begin______not been decided yet.
When they will start and where they go_______not been decided yet.
When and where the meeting will begin_______not been decided.
7.名词性从句的词序
名词性从句在句中要用陈述句语序。

如：
He asked me what was the matter with me.
We’ve heard the news that we’ll move into the new house.
Whatever you say will interest us all.
8.that和what的区别
that引导名词性从句时，在主从句中不以当任何句子成分，也没有任何含义；而what引导名词性从句时，在主从句中都要充当一定主语、宾语、表语或定语，what的意思是:“什么, …的….”What surprised me most is her cheerful expression on her face.
名词性从句专项练习
1. His success was because of ________ he had been working hard.
A. that
B. the fact which
C. the fact that
D. the fact
2. “Is Mary from New York City” “I don't know _______.”
A. from what city does she come from
B. from what city she come
C. what city does she come from
D. what city she comes from
3. ________ makes mistakes must correct them.
A. What
B. That
C. Whoever
D. Whatever
4. The reason why I didn't go to Shanghai was ________ a new job.
A. because I got
B. because of getting
C. I got
D. that I got
5. It worried her a bit ____ her hair was turning grey.
A. while
B. that
C. if
D. for
6. Henry killed the dog. I'll ask him why ________.
A. did he do that
B. he did that
C. he did
D. he has done so
7. Have you seen Henry lately. My boss wants to know ________.
A. how he is getting along
B. how is he getting along
C. what he is getting along
D. what is he getting along
8. It is generally considered unwise to give a child ____ he or she wants.
A. however
B. whatever
C. whichever
D. whenever
9. He asked me ________ with me.
A. what is the trouble
B. what wrong was
C. what was the matter
D. what trouble it is
10. I am sure ________ he said is true.
A. that
B. about that
C. of that
D. that what
11. When and why he came here ________ yet.
A. is not known
B. are not known
C. has not known
D. have not bee
12. I wonder how much ________.
A. does the watch cost
B. did the watch cost
C. the watch costed
D. the watch costs
13. Mary is ________ someone might recognize her.
A. afraid of
B. afraid about
C. afraid that
D. afraid for
14.________ is no reason for dismissing her.
A. Because she was a few minutes late
B. Owing to a few minutes late
C. The fact that she was a few minutes late
D. Being a few minutes late
15. They came to the conclusion ________ by a computer.
A. that not all things can be done
B. because of not all things be done
C. being not all things can be done
D. because not all things can be done
16. Why the explosion occurred was ________ the laboratory attendant had been careless.
A. for
B. because
C. since
D. that
17. I don't doubt ________ he'll come.
A. that
B. if
C. what
D. whether
18. —“Why did you go to the wrong class, Mr. Wang”
—“Well, I forget _______ I was supposed to go to.”
A. which the room
B. which room
C. what was the room
D. what room was it
19. Output is now six times ________ it was before liberation.
A. that
B. which
C. what
D. of which
20. Mary: Helen is a mere washer woman, yet she's now buying a big house.
Carol: Yes. Because she's always saved ________.
A. what little she earns
B. how little she earns
C. for little she earns
D. with little she earns
21. ______ surprised me most was ______ such a little boy of seven could play the violin so well.
A. That…what
B. What…that
C. That…which
D. What…which
22. We gave him ________ help we could.
A. which
B. what
C. that
D. this
23. She is pleased with what you have given him and ________ you have told him.
A. that
B. which
C. all what
D. all that
24. Excuse me would you please tell me ________
A. when the sports meet is taken place
B. when is the sports meet going to be held
C. when is the sports meet to begin
D. when the sports meet is to take place
25. Do you happen to know ________
A. what size shoes he wears
B. how big shoes he wears
C. what is the size of his shoes
D. what number shoes are his
26. This book will show you ________ can be used in other contexts.
A. how you have observed
B. how what you have observed
C. that you have observed
D. how that you have observed
27. Where do you think ________
A. has he gone
B. has he been
C. he's gone
D. was he
28. Do you know ________
A. how many populations there are in the world
B. how much population there is in the world
C. how many the population of the world is
D. what the population of the world is
29. Would you go and see ________ outside
A. what to take place
B. what Tom has happened
C. what is happening
D. what the matter had been
30. The subject of "What is interesting is that I do not even know him." is_______.
A. what
B. interesting
C. What is interesting
D. I
31. ________ I think he is Charles.
A. Who do you think he is
B. Do you think who he is
C. Whom do you think he is
D. Do you think who he is
32. He didn't know which room ________.
A. they lived
B. they lived in
C. did they live
D. did they live in
33. The little boy ate ________ his mother gave him.
A. that
B. which
C. whatever
D. no matter what
34. The city is no longer ________.
A. what it is
B. that it used to be
C. which it was
D. what it used to be
35. My parents used ________ they had to get a new car for me.
A. which
B. that
C. what
D. all what
36. ________ we go swimming every day ________ us a lot of good.
A. If…do
B. That…do
C. If…does
D. That…does
37. ________ was the idea _______ the wife thought of
A. What…that
B. That…what
C. How…why
D. Why…how
38. _______ did he tell his wife ________ he wished to do
A. That…what
B. What…that
C. Where…which
D. Which…where
39. One of the men held the view ________ the book said was right.
A. what that
B. that what
C. that which
D. which that
40. I have no idea ________ or not he has finished the work.
A. if
B. that
C. whether
D. which
1-5.CDCDB 6-10.BABCD 11-15.ADCCA 16-20.DABCA
21-25.BBDDA 26-30.BCDCC 31-35.ABCDC 36-40.DABBC
【定语从句】
在复合句中充当定语的从句叫定语从句。

定语从句的作用相当于形容词，用来修饰主句中的某一名词或代词或整个主句，所以，也称作形容词性从句。

被定语从句修饰的词叫先行词，定语从句一般紧跟在它所修饰的先行词之后。

在先行词和定语从句之间起连接作用的词叫关系词。

关系词有关系代词和关系副词两种。

提示：关系词在定语从句中有三大作用
1. 连接作用——连接先行词和定语从句。

I gave her all the money that I had. 我把我所有的钱都给了她。

（that 连接先特词money和定语从句I had）
2. 替代作用——在定语从句中替代从句所修饰的先行词。

The man who lives nest door is a famous teacher. 住在隔壁的那个人是个名师。

（who 替代the man）
3. 成分作用——在定语从句中作主语、宾语、定语或状语。

I like picrures which are painted in the traditional Chinese style. 我喜欢传统的中国画。

（which在定语从句中作主语）
一、关系代词引导的定语从句
引导定语从句的关系代词主要有who, whom, whose, which, that等。

它们分别代替前面的先行词，并在定语从句中作主语、宾语或定语。

A．Who
指人，在定语从句中作主语。

What was the name of the man who lent you the money?
借钱给你的那人叫什么名字？（定语从句修饰先行词the man）
He who laughs last laughs best. 谁笑到最后谁笑得最好。

（定语从句修饰先行词he）
The chairman of the meeting, who spoke first, sat on my right.
会议主席坐在我右边，他先发言。

（定语从句修饰先行词the chairman）
B．Whom
指人，在定语从句中做宾语。

在口语或非正式文体中，whom可省略或可用who来代替，但在介词后面以及在非限制性定语从句中只能用whom。

There are some people whom/who we like and others whom/who we dislike.
有些人我们是喜欢的，有些人则是我们讨厌的。

（定语从句分别修饰先行词people, others）
The people whom/who I work with are all friendly.
和我一起工作的人都很友好。

（定语从句修饰先行词the people）
Mr. Carter, whom I spoke to on the phone last night, is very interested in our plan.
Mr. Carter, to whom I spoke on the phone last night, is very interested in our plan.
昨晚我在电话里和卡特先生交谈过，他对我们的计划很感兴趣。

（非限制性定语从句中不能用who代替whom）Two men, neither of whom I had ever seen before, came into my office.
两个人来到我的办公室，我以前从未见过他们。

（在介词后面不用who）
C．Whose
人、物皆可，做定语，后面要紧跟被修饰的名词，先行词和后面的名词之间往往是从属关系。

There are some people whose faces you can never forget.
有些人，他们的脸你永远难以忘怀。

（定语从句修饰先行词people）
I saw some trees whose leaves were black because of the polluted air.
我看见一些树的树叶由于空气污染而发黑。

（定语从句修饰行词trees）
D．Which
1．指物，在定语从句中做主语或宾语。

做宾语时常可省略。

English is a language which is easy to learn.
英语是一门容易学的语言。

（which在定语从句中作主语，不能省略）
The children like cookies (which) my wife makes.
孩子们喜欢我夫人做的饼干。

(关系代词which作makes的宾语，可以省略)
2．which引导的非限制性定语从句可以修饰前面的整个主句，相当于and this。

Jim passed his driving test, which surprised everybody.
吉姆通过了驾驶考试，这使大家都感到惊讶。

（定语从句修饰的是整个主句，而不是the driving test）
Sheila couldn't come to the party, which was a pity.
希拉不能来参加聚会，真遗憾。

（定语从句修饰的是整个主句，而不是the party）
3．which在非限制性定语从句中有时也可以作定语。

John stayed here for a week, during which time we visited the West Lake together.
约翰在这里呆了一星期，在此期间我们一起游了西湖。

It might snow this weekend, in which case we won't go to Beijing.
周末可能下雪，在这种情况下，我们就不去北京了。

E．That
指人时，相当于who 或whom；指物时，相当于which。

在定语从句中作主语或宾语（做宾语时常可省略）。

He is the man that lives next door.
他就是住在隔壁的那个人。

（定语从句修饰先行词the man，作主语）
I don't like stories that have unhappy endings.
我不喜欢结尾悲伤的故事。

（定语从句修饰先行词stories，作主语）
The dress (that) Ann bought doesn’t fit her very well.
安买的衣服不太合身。

（定语从句修饰先行词the dress，that作宾语可省略）
Is there anything (that) I can do for you?
有我能为你效劳的事吗？（定语从句修饰先行词anything，that作宾语，可省略）
提示：
在口语中，that有时还可以作关系副词，相当于when或介词+which 结构。

We left the day (that) he arrived. 他来的那一天，我们就走了。

（that替when）
He doesn't see things the way (that) we see them. 他看问题的方法和我们不一样。

（that代替in which）Imagine the speed (that) he drives his car! 很难想象，他开车的速度那么快！（that代替at which）
F．As
as可以在限制性定语从句和非限制性定语从句中作主语或宾语。

① 在限制性定语从句中，as可跟在由such, so, the same修饰的先行词之后。

Such men as heard him were deeply moved.
听过他说话的人，都会深受感动。

（as在定语从句中作heard的主语）
I've never heard such stories as he tells.
我从未听过像他讲的这样的故事。

（as在定语从句中作tell的宾语）
He lifted so heavy a stone as no one else can lift.
他搬起别人都搬不起的大石头。

（as在定语从句中lift的宾语）
比较：
在the same as结构中，as也可用that代替。

但严格地说，the same as强调相同，the same that注重同一。

She wore the same dress as her younger sister wore.
她穿着跟她妹妹所穿的一样的衣裙。

（as指的是与先行词相似的同类事物）
She wore the same dress that she wore at Mary's wedding.
她穿着她在玛丽婚礼上穿过的同一条连衣裙。

（that指的是与先行词同一事物）
① 在非限制性定语从句中，as可代表主句整个句子，引导的定语从句可以放在主句之前或主句之后，一般用逗号与主句分开。

As everyone knows, Taiwan belongs to China.
众所周知，台湾属于中国的领土。

He is from the outh, as we can know from his accent.
他是南方人，这一点我们从他的口音可以知道。

必背：
一些由as引导的定语从句常位于句首，已形成了固定的说法。

as is known to all 这是众所周知的
as has been said before 如前所说
as is often the case 情况常常如此
as may be imagined 这可以想象得出
as has been pointed out 正如已经指出的那样
as often happens 这种情况常常发生
由as, which 引导的非限定性定语从句，as和which可代整个主句，相当于and this或and that。

As一般放在句首，which在句中。

例如：
As we know, smoking is harmful to one\'s health. 如我们所知，吸烟有害健康。

The sun heats the earth, which is very important to us. 太阳使地球暖起来，这对我们人类很重要。

典型例题
1）Alice received an invitation from her boss, ___came as a surprise.
A. it
B. that
C. which
D. he
答案C. 此为非限定性从句，不能用that修饰，而用which.，it 和he 都使后句成为句子，两个独立的句子不能单以逗号连接。

况且选he句意不通。

2）The weather turned out to be very good, ___ was more than we could expect.
A. what
B. which
C. that
D. it
答案B。

which可代替句子，用于非限定性定语从句，而what不可。

That 不能用于非限定性定语从句，it不为连词，使由逗号连接的两个句子并在一起在英语语法上行不通。

3）It rained hard yesterday, ____ prevented me from going to the park..
A. that
B. which
C. as
D. it
答案B. as 和which在引导非限制性定语从句时，这两个关系代词都指主句所表达的整个意思，且在定语从句中都可以作主语和宾语。

但不同之处主要有两点：
（1）as 引导的定语从句可置于句首，而which不可。

（2）as 代表前面的整个主句并在从句中作主语时，从句中的谓语必须是系动词；若为行为动词，则从句中的关系代词只能用which.。

在本题中，prevent由于是行为动词，所以正确选项应为B。

as 的用法
例1. the same…as；such…as 中的as 是一种固定结构, 和……一样……。

例如：
I have got into the same trouble as he （has）. 我碰到了跟他一样的麻烦。

例2. as可引导非限制性从句，常带有\'正如\'。

例如：
As we know, smoking is harmful to one\'s health. 如我们所知，吸烟有害健康。

As is known, smoking is harmful to one\'s health.
As是关系代词。

例1中的as作know的宾语；例2中，它充当从句的主语，谓语动词know要用被动式。

G．介词+关系代词引导的定语从句
介词+关系代词引导的定语从句是一种非常常见但也比较复杂的定语从句结构。

1. 介词+关系代词中介词的位置
关系代词whom, which在从句中作介词宾语时，可以跟介词一起放在从句与主句之间（that, who不可以），也可以把介词放在从句中有关动词的后面，使关系代词紧跟它所修饰的先行词。

He is a man of rich experience, from whom much can be learned.
= He is a man of rich experience, whom much can be learned from.
他是个经验丰富的人，从他那儿可以学到很多。

The school in which he once worked is a key school.
=The school (which that) he once worked in is a key school.
他曾经工作过的学校是一所重点学校。

The manager in whose company I work pays much attention to improving our working conditions.
=The manager whose company I'm working in pays much attention to improving our working conditions.
我就职的那家公司经理十分注意改善我们的工作条件。

2．介词+关系代词的常见结构
①介词+which whom
This is the famous singer about whom we have often talked.
这就是那位我们经常谈论的著名歌唱家。

Fortunately we had a map, without which we would have got lost.
很幸运，我们带了一张地图，如没有的话，我们就会迷路了。

①名词+of+ which /whom
Please pass me the book the cover of which is blue. 请把那本蓝封面的书递给我。

（也可用whose cover）
①数词+of+ which /whom
She's got three lucky pens, two of which she never uses.
她有三只幸运笔，其中两只从未用过。

①代词+of+ which /whom
In the basket I find many apples, some of which have gone bad.
我发现篮子里有好些苹果，有些已经坏了。

There are fifty students in our class, most of whom are from big cities.
我们班有50个学生，其中大多数来自大城市。

①最高级+of+ which /whom
China has thousands of islands, the largest of which is Taiwan. 中国有数千个岛屿，其中最大的是台湾。

①介词+which+名词
He usually returns home at ten, at which hour his father locks all the doors ad windows.
他通常十点钟回家，在这时候他爸爸锁好所有的门窗。

His wife got seriously ill, in which case he had to give up the chance of going abroad.
他的妻子病得很重，在这种情况下，他不得不放弃出国的机会。

3．关系代词前介词的选择
在介词+关系代词引导的定语从句中，应注意介词的正确选择。

① 根据后面动词和介词的搭配关系选择。

The two things of which they felt proud were Jim's watch and Della's hair.
他们引以为豪的两样东西是吉姆的手表和德拉的头发。

（feel proud of是固定搭配词组）
In the dark street there was not a single person to whom she could turn for help.
在漆黑的街道上没有一个她可以求助的人。

（turn to sb. for help是固定搭配词组）
①根据与前面名词的搭配关系选择。

I'll never forget the ay on which I first met him.
我永远忘不了我第一次遇见他的那一天。

(the day前面一般用介词on)
Can you imagine a proper situation in which the expression can be used?
你能设想一个使用这个词语的场合吗？(a situation前面一般用in)
①有时须同时考虑动词和介词的搭配关系及介词和名词的搭配关系。

Is that the house in which you once lived
那就是你曾经住过的房子吗？(Live in the house)
①根据所要表达的意思来确定。

This is my pair of glasses, without which I cannot see clearly.
这是我的眼镜，离了它我什么也看不清。

注意：
当关系代词在定语从句中作主语时，谓语动词应与先行词的人称和数保持一致。

I, who am your best friend, will do all that I can to help you.
我是你的好朋友，我会尽我一切所能来帮你。

The family, who are fond of music, go to the concert once a month.
这家人很爱音乐，他们每月都去听一次音乐会。

He is one of the boys in our class who speak English well.
他是班上英语说得很好的男生之一。

（one of +复数名词+关系代词引导的定语从句谓语动词用复数形式）
He is the only one of the boys in our class who speaks English well.
他是班上唯一英语说得很好的男生。

（the (only) one the very one the right one of +复数名词+关系代词引导的定语从句谓语动词用单数形式）
二、关系副引导的定语从句
引导定语从句的关系副词有when, where或why等。

when, where, why分别在定语从句中作状语，在意义上相当于介词+which结构，分别代替表示时间、地点或原因的先行词。

A．when
指时间，在定语从句中作时间状语。

I still remember the day when I first came to this school.
我仍然记得我第一次来到这所学校的那一天。

(when= on which)
He came at a time when we needed him most.
他是在我们最需要他的时候来的。

(when= at which)
We will never forget the year 1949, when th People's Republic of China was founded.
我们永远忘不了1949年，那是中华人民共和国成立的一年。

(when= in which)
B．where
指地点，在定语从句中作地点状语。

I recently went back to the town where I was born.
我最近曾回过一次我出生的城市。

(where = in which)
I would like to live in a country where there is plety of sunshine.
我想住在一个阳光充足的国家。

(where = in which)
What's the name of the place where you spent your holiday
你度假的那个地方叫什么名字？(where = at which)
C．why
指原因，在限制性定语从句中作原因状语。

Please tell me the reason why you missed the plane.
请告诉我你误机的原因。

(why = for which)
Te reason why he was punished is unknown to us.
他受惩罚的原因我们都不知道。

注意:
无论是关系代词，还是关系副词，都在定语从句中取代了先行词，因此，先行词在定语从句中不复出现。

【误】This is the book that I borrowed it yesterday.
【正】This is the book that I borrowed yesterday.
这就是我昨天借的书。

（that在定语从句中取代了先行词the book，作borowed的宾语，因此，要去掉it）【误】The English Corner is the place where people often go there to practise their spoken English.
【正】The English Corner is the place where people often go to practise their spoken English.
英语角是人们经常去练习英语口语的地方。

（where在定语从句中取代了先行词the pace，作go的状语，因此，要去掉there）
三、限制性定语从句和非限制性定语从句
根据定语从句在句中所起的作用，可分为限制性定语从句和非限制性定语从句两大类。

A．限制性定语从句
限制性定语从句是先行词在意义上不可缺少的定语，用于修饰和限定先行词。

如果去掉，主句的意思就不完整或失去意义。

书写时不用逗号与先行词分开。

This is the boy who broke the window.
这就是打破窗子的孩子。

（the boy是先行词，who broke the indow是限制性定语从句，明确指出the boy是打破窗子的那个孩子）
I have a book which teaches English grammar.
我有一本讲解英语语法的书。

（a book是先行词，which teaches English grammar是限制性定语从句，修饰the book）The people whom you met in the hall are from Japan.
你在大厅见到的那些人来自日本。

（定语从句whom you met in the hall定先行词the people）
B．非限制性定语从句
非限制性定语从句在意义上只是一个附加修饰语，对先行词或主句作些附加的说明。

如果去掉，主句的意思仍然清楚。

书写时往往用逗号与先行词分开。