定语从句讲解
一、了解定语从句及相关术语
1. 定语从句：修饰一个名词或代词的从句称为定语从句，一般紧跟在它所修饰的先行词后面，相当于形容词在句中作定语。
2. 先行词：被修饰的名词或代词叫先行词。
3. 关系词：引导定语从句的关联词称为关系词。关系词有关系代词和关系副词。关系代词有that，which，who，whom，whose，as等；关系副词有where，when，why等。
He is the man who I want to see. 他就是我想见的人。
先行词 关系词 定语从句
二、掌握关系代词及其作用
最常用的关系代词是who, whom, whose, that，which和as。关系代词同时起了两个作用。它们可以像别的代词一样，可以代表一个名词，在定语从句中用作主语或宾语，同时，它们又起到了连词的作用，把主句和从句连接起来。
1. who指人，在定语从句中一般做主语。如：
Do you know the man who is speaking to your father? 你认识和你爸爸讲话的那个人吗？(定语从句修饰先行词the man，who在定语从句中作is speaking的主语）
This is the stranger who helped us yesterday. 这是昨天帮助我们的那个陌生人。
She is the girl who works hard at maths. 她就是那个努力学习数学的女孩。
2. whom指人，在定语从句中作宾语。在口语或非正式文体中，whom可以省略。如：
He is the man (whom) we just talked about. 他就是我们刚才谈论的那个人。
The boy (whom) we met in the street yesterday is my classmate. 我们昨天在大街上遇到的那个男孩是我的同学。
3. whose既可以指人，也可以指物，在定语从句中作定语修饰它后面的名词。如：
This is the girl whose father is a policeman. 这就是那个爸爸是警察的女孩。
They live in a house whose windows face south. 他们住在一座窗子朝南的房子里。
4. which指物，在定语从句中做主语或宾语。作宾语时可以省略。如：
Physics is a subject which is very difficult to learn. 物理是一门很难学的科目。（在定语从句中做主语，不能省略）
Apples are the fruit (which) she likes best. 苹果是她最喜欢的水果。
5. that既可以指人，也可以指物，在定语从句中做主语或宾语。指人时，相当于who或whom；指物时，相当于which。that在从句中作宾语时可省略。如：
He is the man that lives next door. 他就是住在隔壁的那个人。
We like programs that are very interesting. 我们喜欢有趣的节目。
She is the woman （that） we saw in the bookshop. 她是我们在书店见到的那名妇女。
6. that指人时，相当于who或者whom；指物时，相当于which。在定语从句中作主语或者宾语。如：
The number of the people that/who come to visit the city each year rises one million. 来这个城市参观的.人数每年增长一百万。
Where is the man that/whom I saw this morning? 今天早晨我看见的那个人在哪里？
三、掌握关系副词及其作用
关系副词有when、where、why，他们在引导定语从句时，既在定语从句中充当状语，又起连接作用。
1. When指时间，在定语从句中充当时间状语。如：
I still remember the day when I first came to Dalian. 我仍然记得第一次来大连那天的情景。
He told me the date when he joined the party. 他告诉了我他入党的时间。
They stayed with me for three weeks when they drank all the wine I had.他们和我一起住了三个星期，在那三周里，把我所有的葡萄酒都喝光了。
2. where指地点、在定语从句中充当地点状语。如：
This is the house where we lived when we were young. 这就是我们小时候住的房子。
This is the village where I grew up. 这就是我长大的那个村庄。
Hangzhou is a city where there is a beautiful lake. 杭州是个有一个美丽的湖泊的城市。
3. why指原因，在定语从句中充当原因状语。如：
I know the reason why he was late for the meeting. 我知道他开会迟到的原因。
Do you know the reason why he refused the invitation? 你知道他拒绝应邀的原因吗？
That is the reason why I’ve changed so much. 那就是我变化这么快的原因。
四、学习定语从句应该注意的问题
1. 关系代词和关系副词的选用
如果先行词是表示时间或地点的名词，不能就一律断定要用关系副词when或where，务必要看引导词在从句中作什么成分，如果作状语，用关系副词，如做主语或宾语要用关系代词。当reason做先行词时，也需注意其引导词在从句中作什么成分，不能断定一概用why来引导。如：
I’ll never forget the time when we worked together. 我将永远不会忘记我们一起工作的时光。 （work是不及物动词，when在定语从句中作状语，故用关系副词。）
I’ll never forget the time (which/that) we spent together. 我将永远不会忘记我们一起渡过的时光。
spend是及物动词，which/that在定语从句中作宾语，故用关系代词，也可以省略。）
This is the factory where he worked before. 这是他以前工作过的工厂。（work是不及物动词，where在定语从句中作状语。）
This is the factory which/that he visited before. 这是他以前参观过的工厂。（visit是及物动词，which/that在从句中作宾语，亦可省略。）
The reason why I was absent yesterday was that I was ill. 我昨天缺席的原因是我生病了。定语从句中缺状语，表示原因，故用关系副词why）
The reason that he explained for his being late was that he had missed the early bus.他所解释的迟到的原因是他误了头班汽车。（explain是及物动词，that在从句中作其宾语）
再看一个例题：
（1）This is the factory ________ I visited last year.
（2）This is the factory _______ I worked last year.
（3）This is the factory _______ produces all kinds of TV sets.
A. where B. which C. whom D. whose
以上三个句子只有细微的差别，但答案却不同：（1）和（3）选B. which。（2）选A. where。做这种题时，要看先行词与定语从句中谓语动词之间的关系；（1）中是动宾关系，即I visited the factory，因此选which。（2）中factory应在定语从句中作地点状语，即：I worked in the factory，因此选where。（3）中是作定语从句中的主语，不作地点状语，因此选which。
2. 限制性定语从句只能用that的几种情况
1）当先行词是anything, everything, nothing (something 除外), few, all, none, little, some等代词时，或者是由every, any, all, some, no, little, few, much等修饰时。如：
Have you taken down everything that Mr. Li has said? 你把李先生说的话都记下来了吗？
There seems to be nothing that seems impossible for him in the world. 在他看来世界上似乎没有不可能的是。
All that can be done has been done.所有能做的事情都做了。
2）当先行词被序数词修饰。如：
The first place that they visited in London was the Big Ben. 他们在伦敦参观的第一个地方就是“大本钟”。
3）当先行词被形容词最高级修饰时。如：
I think the film Assembly is the best film that I have seen. 我认为电影《集结号》是我看过的最好的电影。
4）当形容词被the very, the only 修饰时。如：
This is the very dictionary that I want to buy. 这就是我想买的那本辞典。
After the fire in his house, the old car is the only thing that he owned. 房子失火以后，那辆旧汽车就是他唯一的财产。
5）当先行词前面有who, which等疑问代词时。如：
Who is the man that is standing there? 站在那儿那个人是谁？
Which is the T-shirt that fits me most?哪件T恤适合我穿？
6）当先行词既有人，也有动物或者物体时。如：
Can you remember the scientist and his theory that we have learned?你还记得我们学到的那个科学家及他的理论吗？
3. 区分定语从句和同位语从句
1）定语从句修饰先行词，它和先行词是修饰关系；同位语从句说明先行词的具体内容，是补充说明的关系。如：
The plane that has just taken off is for London. 刚起飞的飞机是去伦敦的。（定语从句）
The fact that he has been dead is clear. 他已经死亡的事实是清楚的。（同位语从句）
2）定语从句由关系代词或者关系副词引导，关系词在句中充当成分，有时可以省略；同位语从句主要由that引导，在句中一般不做成分；句子也可以由when, where, how, why, whether, what等词引导，充当成分。如：
The problem that we are facing now is how we can collect so much money.我们现在面临的问题是怎样筹集那么多钱。 （定语从句）
The problem how we can collect so much money is difficult to solve. 怎样筹集钱的问题很难解决。（同位语从句）
3）同位语从句和先行词一般可以用be动词发展成一个完整的句子，而定语从句不可以。如：
The fact that the earth moves around the earth is known to all.地球绕着太阳转这一事实是众所周知的。（同位语从句）
The fact is that the earth moves around the earth. 这个事实就是地球绕着太阳转。
3. 关系副词when, where, why的含义相当于"介词+ which"结构，因此常常和"介词+ which"结构交替使用，例如：
There are occasions when (on which) one must yield. 任何人都有不得不屈服的时候。
Beijing is the place where (in which) I was born. 北京是我的出生地。
Is this the reason why (for which) he refused our offer? 这就是他拒绝我们帮助他的理由吗？
4. that代替关系副词
that可以用于表示时间、地点、方式、理由的名词后取代when, where, why和"介词+ which"引导的定语从句，在口语中that常被省略，例如：
His father died the year (that / when / in which) he was born. 他父亲在他出生那年逝世了。
He is unlikely to find the place (that / where / in which) he lived forty years ago. 他不大可能找到他四十年前居住过的地方。
五、考点链接
1. 考查that
Do you still remember the chicken farm _______ we visited three months ago?
A. where B. when C. that D. what (2005北京春)
【解析】C、从句中visited 是及物动词，而且没有宾语，要用关系代词引导定语从句。
2. 考查who，whom和whose
1）Women _______ drink more than two cups of coffee a day have a greater chance of having heart disease than those ________ don’t.
A. who; 不填 B. 不填; who C. who; who D. 不填表; 不填（2006北京卷）
【解析】C、第一空定语从句缺少主语，必须用who，不能省略；第二空也是关系代词作主语，不能省略。
2）Look out! Don’t get too close to the house______ roof is under repair.
A. whose B. which C. of which D. what （2006福建卷）
【解析】A、从句中缺少的是roof的定语，在定语从句中关系代词作定语用whose，whose可以修饰人，也可以修饰物。
3. 考查when，where和when
1）—Where did you get to know her?
—It was on the farm _________ we worked. （2007 山东卷）
A. that B. there C. which D. where
【解析】D、work是不及物动词，不需要宾语，所以用where引导定语从句。
