I. 定语从句起了形容词的作用，在句中修饰一个名词或代词。被修饰的词叫做先行词，引导定语从句的词叫关系词，他的作用一是放在先行词与定语从句中间起了连接作用，二是在从句中担当一个成分，并与先行词保持数的一致。
| 关系词 | 先行词 | 从句成分 | 例 句 | 备 注 | |
| 关系代 词 | who | 人 | 主语 | Do you know the man who is talking with your mother? | whom, which和that在从句中做宾语时，常可以省略，但介词提前时后面关系代词不能省略，也不可以用that |
| whom | 人 | 宾语 |
Mr. Smith is the person with whom I am working The boy (whom) she loved died in the war.. |
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| whose | 人或物 | 定语 |
I like those books whose topics are about history. The boy whose father works abroad is my deskmate. |
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| that | 人或物 | 主语，宾语 |
A plane is a machine that can fly. She is the pop star (that) I want to see very much. |
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| which | 物 | 主语，宾语 |
The book (which) I gave you was worth $10. The picture which was about the accident was terrible. |
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| as | 人或物 | 主语，宾语 |
He is such a person as is respected by all of us. This is the same pen as I lost yesterday. |
as做宾语一般不省略 | |
| 关系副 词 | when | 时间 | 时间状语 | I will never forget the day when we met there. | 可用on which |
| where | 地点 | 地点状语 | This is the house where I was born. | 可用in which | |
| why | 原因 | 原因状语 | I can’t imagine the reason why he turned down my offer. | 可用for which | |
| 情 况 | 用法说明 | 例 句 |
| 只用that的情况 |
1.先行词为all, everything, anything, nothing, little, much,等不定代词时 2.先行词被all, any, every, each, much, little, no, some, few等修饰时 3.先行词有形容词最高级和序数词修饰时 4.先行词既指人又指物时 5.先行词被the only, the very修饰时 6.句中已经有who或which时，为了避免重复时 |
1.He told me everything that he knows. 2.All the books that you offered has been given out. 3.This is the best film that I have ever read. 4.We talked about the persons and things that we remembered. 5.He is the only man that I want to see. 6.Who is the man that is making a speech? |
| 只用which, who, whom的情况 |
1.在非限制性定语从句中，只能用which指代物，用who/whom指人 2.在由“介词+关系代词”引导的定语从句中，只能用which指物，whom指人。 3.先行词本身是that时，关系词用which, 先行词为those, one, he时多用who。 |
1.He has a son, who has gone abroad for further study. 2.I like the person to whom the teacher is talking. 3.Those who respect others are usually respected by others. |
| 从句 | 区 别 | 例 句 |
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限制性 定语从句中 |
名词前有such和the same修饰时，关系代词用as,不能用which |
He is not such a fool as he looks. Don’t read such books as you can’t understand. |
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非限制性 定语从句中 |
as和which都可以指代前面整个主句。如果有“正如，象”的含义，并可以放在主句前，也可以放在后面，那么用as；而which引导的从句只能放主句后，并无“正如”的意思。 |
They won the game, as we had expected. They won the game, which we hadn’t expected. As is well known, he is a famous film star in the 1980s. |
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the same... as和 the same ...that |
the same... as指同类事物 the same ...that 指原物 |
That’s the same tool as I used last week.（同类工具，不是同一把） That’s the same tool that I used last week.那就是我上周用过的工具。 |
IV.定语从句与其它从句（句型）的区别
| 类 别 | 区 别 | 例 句 |
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定语从句 与 并列句 |
定语从句与并列句的主要区别在于：并列句有像and，but，so等并列连词或两个句子用分号连接，这时就不能再用引导定语从句的关系词了。 |
①Mr Li has three daughters，none of _____ is an engineer． ②Mr Li has three daughters，but none of _____ is a dancer． 从结构上看，①小题是定语从句，故填whom； ②小题有并列连词but，是并列句，故填代词 them。 |
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定语从句 与 状语从句 |
定语从句的前面有名词作先行词，而状语从句没有先行词。 |
This is the place where we used to live a few years ago. 这是几年前我们居住的地方。（定语从句，先行词为the place） Let’s go where we can find a better job. 我们到能找到更好的工作的地方去吧。（地点状语从句） |
| 定语从句修饰、限制、说明名词，只能放在先行词的后面，而状语从句说明动作发生的情况，并且可以放在主句的前面。 |
Do you know the time when the class is over? 你知道下课的时间吗？（定语从句） It was already five o’clock when the class was over. =When the class was over, it was already five o’clock. 当下课时己经是5点了。（时间状语从句） |
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| When, where和why在引导定语从句时可以用“介词＋which”的结构来替换，在引导状语从句时却不行。 |
This is the factory in which (where) his father once worked. 这就是他的父亲曾经工作过的那个工厂。（定语从句） Put back the book where it was. 把书放回原处。（状语从句） |
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| 定语从句中的关系词在从句中充当某种句子成分，因此去掉它则从句成分不完整；而结果状语从句中的连接词在从句中不作任何成分，去掉后从句的成分仍然完整。 |
It is such an interesting book as we all like. 它是我们大家都喜欢的如此有趣的书。 （as用作动词like的宾语，它引导的是定语从句） It is such an interesting book that we all like it. 它是一本如此有趣的书，我们大家都喜欢它。 （that不充当句子成分，故它引导的是结果状语从句） |
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定语从句 与 同位语从句 |
定语从句在复合句中相当于形容词，对先行词起修饰、描述或限制的作用，与先行词之间有从属关系。同位语的作用相当于名词，对前面的名词给予补充说明或进一步解释，是前面名词的具体内容,与先行词之间是同位关系。 |
The news that she had passed the exam made her parents very happy. 她考试及格的消息使她父母亲很高兴。（同位语从句） 此句中的同位语从句 The news that she had passed the exam 可以改写成表语从句：The news is that he passed the exam. The news that he told us interested all of us. 他告诉我们的消息使大家都感兴趣。（定语从句） The news that he told us 是定语从句，此句不能改写为：The news is that he told us. |
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定语从句 与 强调句 |
强调句的结构为“It is／was＋被强调部分＋that＋从句”。被强调部分可以是除谓语以外的任何成分，当被强调部分是人时，还可用who代替that。这一句型中，一定不能因为被强调部分是表时间或地点的词就用when或where代替 that。 |
①It is on the morning of May 1st _____ I met Liang Wei at the airport． ②It is the factory _____ Mr Wang works． 从结构上看： ①小题是强调句，故填 that。 ②小题则是定语从句，用上述方法转换便知the factory前差个介词in，故填 where。 |
1．I can still remember the sitting room my mother and I used to sit in the evening．
A．what B．which C．that D．where
2．The man was a friend of mine．
A．that you just talked to B．whom you just talked to him
C．who you just talked to him D．you just talked
3．1’ll never forget the place I visited ten years ago.
A．where B．that C．in which D．what
4． We all know，oil and water don’t mix up．
A．That B．What C．Which D．As
5．All is needed is a Supply of oil．
A．the thing B．that C．what D．which
6．Last night we went to Ann’s party， we enjoyed very much．
A．when B．that C．which D．where
7．There is a mountain the top is always covered with snow．
A．of that B．of which C．its D．that
8．This is the only dictionary he often turns to for help．
A．which B．that C．what D．one
9．I hope you will find this valley a beautiful place you may spend your weekend．
A．that B．w hich C．when D．where
lO．Football， is a very interesting game，is played all over the world．
A．that B．which C．it D．who
11． has already been pointed out，grammar is not a set of dead rules．
A．As B．It C．That D．Which
12．Alice received an invitation from her boss, came as a surprise．
A．it B．that C．which D．he
13． leaves the room last is asked to turn off the lights．
A．Anyone B．Who C．Everyone D．Whoever
14．The wolves hid themselves in the place couldn’t be found．
A．that B．where C．in which D．in that
15．We will be shown around and city；schools，museums，and some other places， other visitors seldom go．
A．what B．which C．where D．when
定语从句
1-5 DABDB 6-10 CBBDB 1l-15 ACDAC
