http://s3/bmiddle/003vmQtlzy7kfm8cioE60

定义：

在复合句中，修饰名词或代词的从句叫定语从句， 被修饰的名词或代词叫先行词， 引导定语从句的引导词分为：关系代词 who, whom, whose, which, that等，和关系副词where, when, why等， 关系代词和关系副词在定语从句中担任句子成份，不可省略。

1.由who引导的定语从句中，who用作主语， 如： This is the boy who often helps me.

2.由whom引导的定语从句中，whom用作宾语，如：The man whom you are waiting for has gone home.

3.由whose引导的定语从句中，whose用作定语， 如： Do you know the girl whose skirt is white?

4.由which引导的定语从句中，which用作主语或谓语动词的宾语或介词的宾语。

  如： The room in which there is a machine is a workshop（车间）.

       The river which is in front of my house is very clean.

       This is the pen which you want.

   注意 ​：

   (1) whom, which用作介词宾语时，介词可放在 whom、which之前，也可放在从句原来的位置上；但在含有介词的动词固定词组中，介词只能放在原来的位置上。

       如： He is the very person whom we must take good care of.

   (2) 引导非限制性定语从句时，必须用关系代词which，不用that。

       如：I have lost my bag, which I like very much.

   (3)关系代词在句中作主语时，从句的谓语动词的人称和数必须和先行词保持一致。

5.由that引导的定语从句中，that可以指人或物，在从句中作主语或谓语动词的宾语，但不能放在介词后面作介词宾语，即介词后只能用which,不能用that.

   如：The book that I bought yesterday was written by Lu Xun.

   注意：在下面几种情况下必须用 that引导定语从句。

   (1) 先行词是不定代词something, nothing, anything，everything等, 如：All that we have to do is to practise English.

   (2) 先行词被序数词或形容词最高级所修饰，如：The first letter that I got from him will be kept in my case .

   (3) 先行词被all, any, every, each, few, little, no, some等修饰，如：I have eaten up all the food that you gave me .

   (4) 先行词被the only, the very, the same, the last修饰时, 如:H e is the only person that I want to talk with.

   (5) 先行词既有人又有物时，如:They talk about persons and things that they met .

   (6) 当句中已有who时 ,为避免重复，如：Who is the man that is giving us the class?

6. 由when, where, why引导的定语从句，如: I don't know the reason why he was late.

    This is the place where we have lived for 5 years.

    I'll never forget the day when I met Mr Li for the first time.

    注意：先行词是表示地点时，如果从句的谓语动词是及物的，就用 that(which)，如果从句的谓语动词是不及物的，就用where引导。This is the house which /that he has lived in for 15 years.(where he has lived for 15 year.)

7、 限制性定语从句和非限制性定语从句：

（1）限制性定语从句是句中不可缺少的组成部分，主句和从句之间不用逗号隔开，引导限制性定语从句的关系代词有：who,whom,whose,which,of which等，这些关系代词都不可省。

（2） 非限制性定语从句是对主句先行词的补充说明，没有这种从句，不影响主句意思的完整性，一般用逗号将其与主句隔开，关系代词用which,不用that；指人时可用who.  Eg: I have two brothers, who both are both students.

8、 如何简化定于从句

（1） 定语从句简化为形容词或形容词短语作后置定语。  

    Eg:My grandfather lives in a village which is far away from here.   →My grandfather lives in a village far away from here.

(2) 定语从句简化为现在分词或现在分词短语作前置或后置定语。  

    Eg:The man who is standing under the tree is our English teacher.   →The man standing under the tree is our English teacher.

    I saw the house that was burning（燃烧）at that time. → I saw the house burning at that time.

(3) 定语从句简化为过去分词短语作后置定语。

    Eg:I like to eat the cakes which are made by my mother.   →I like to eat the cakes made by my mother.

(4) 定语从句简化为不定式作后置定语。

    Eg:She is always the first person that comes to school .主动   →She is always the first person to come to school .

    The report which will be given tomorrow is very importance for us.被动    →The report to be given tomorrow is very importance for us.

(5) 定语从句简化为what从句。

    Eg:I couldn’t remember the words that he said .   I couldn’t remember what he said.

附加练习题：

1. The silk _______ is made in Hangzhou sells well.

   A. that B.who C. what D. /

2. The man_______today left this message for you.

   A.called B.has called C.whom called D.who called

3. Do you live near the building ______color is yellow?

   A. that B.which C.whose D. its

4. He helped his father on the farm ______they lived.

   A. which B.that C.when D. where

5. I’m one of the boys_____never late for school.

   A.that is B.who is C.who are D.who am

6. All_____should be done has been done.

   A.what B.which C.that D.whatever

7. Jack told me everything _______he knew about it.

   A. what B.that C.which D.who

8. My father works in the factory ______this type of truck is made.

   A.in where B.in which C.from which D.of which

9. The school_______we visited last week was built in 1956.

   A./ B.where C.that D.both A and C

10. This is one of the best films_______I have ever seen.

    A.which B.that C.of which D.of that