I.知识点归纳

一．概念

  1．由一个句子作定语，修饰句中一个名词或代词，有时也可以修饰整个句子或句中的部分内容，这样的从句就是定语从句，被其修饰的名词或代词叫先行词。

  2．关系词分为两大类，即关系代词(that which who whom whose as)和关系副词(when where why)，其作用一是引出一个定语从句，二是代替其所修饰的先行词，三是在句中充当某个句子成分。

二．定语从句的注意点

1.which和 that用法辨异

1)只能用that的情况

①当先行词是不定代词all, much, little, few, none, , anything, nothing，everything等时 (something后可以用which)

②先行词既指人又指物时.They talked about things and persons that they remembered.

③先行词被序数词或形容词的最高级修饰时

④先行词被the very, the only, the last, any, every, no ,all修饰时

⑤先行词是疑问词who, what, which时或先行词 在由which, who引导的特殊疑问句中时

Who that you have ever seen can beat him in chess?

⑥关系词在从句中作表语时.

He is not that man that he was.（他已不是过去的他了）

2) 只能用which的情况

①引导非限制性定语从句修饰某物或整个句子时

②如果句中有两个定语从句，其中一个用了that,另一个最好用which.  

  Let me show you the novel that I borrowed from the library which was newly open to us.

③先行词本身就是that时

I have that which you gave me.  （我有你给的那个）

④ 介词之后须用which. This is the one of which I’m speaking.这就是我所讲的那个。

2.只能用who 的情况

1)先行词是指人的不定代词one, ones, nobody, everyone, anyone或all时  2)先行词是those和people时  3)在there be开头的句中  4)先行词指人时后有一个较长的定语或被其他成分隔开时

5)在非限制性定语从句中

3.as和which用法辨异

1)只能用as的情况

     ①as通常与the same, such, so或as搭配使用

     ②位于句首的定语从句用as引导

     ③as常解释为“正如...的那样”, “ 正像...”，如：

as is known to all, as we all know, as has been said before, as was expected, as is said above, as is mentioned above, as is reported in the newspaper等

2)只能用which的情况

①充当定语从句的主语时， 从句的谓语动词是联系动词或被动语态时用as, which都可以，从句的谓语是行为动词时，只用which

②接在介词后面时只用which

    ③当从句的谓语是否定形式或接一个复合宾语时， 只能用which，不用as

He admires everyone in the class, which I find quite strange.

4.the same... as 和 the same ...that的用法辨异.

That’s the same tool as I used last week.（同类事物）

That’s the same tool that I used last week. 那就是我上周用过的工具。（指原物）

5.the way 做先行词时，定语从句可由that, in which 引导或不用引导词。

6.介词+which/whom/whose

This is the boss in whose company his elder sister is working.

7.定语从句和同位语从句之间的区别

①定语从句的先行词是名词和代词，定语从句起限制、修饰先行词的作用， 而同位语从句的先行词是抽象名词，它解释、说明先行词的具体内容：

   The news that our team has won is true. （ 同位语从句）

   The news that he told me is true. (定语从句)

 ②先行词在从句中作成分是定语从句，先行词在从句中不作成分是同位语从句

   The news (that) he told me is exciting.（作宾语可省）

   The news that he has been elected president of the United States is true. （引导同位语从句不可省）

8.先行词是 reason在从句 中作主语，宾语，关系词用which/that/as,作状语用why

   This is the reason that he told me yesterday.

   This is the reason why he was late for the meeting.

9.先行词是地点名词如在从句中作主语，宾语，关系词用which/that/as, 作状语用where.

That is the factory which/that produces 100,000TV sets a year.

That is the factory where/in which his father once worked.

10.先行词是“时间名词” 如在从句中作主语，宾语，关系词用which/that/as, 作状语用when.

I’ll never forget the days which/that we spent on that lonely island.

I’ll never forget the day when/on which I joined the Party.

11.but 作为关系词引导定语从句。

There is no mother but loves her children=There is no mother who does not love her children

12.在下列情况下必须使用非限制性定语从句。

①当先行词为专有名词或球类、疾病、学科等独一无二的事物时。

He caught SARS, which threatened people a lot.

They will fly to Paris, where they plan to stay two or three days.

Football, which is now played in over 100 countries, is the most popular game in the world.

②当主句内容完整，先行词意义明确时。

His house, which was finished only last month, was burnt down to the ground last night.

We will put off the outing till next week, when we won’t be so busy.

③当定语从句修饰整个主句时。

They have invited me to visit their country, which is very kind of them.

They moved the fallen tree, which took them a long time.

⑤当定语从句修饰主句中的一部分时。

She was very patient towards the children, which her husband seldom was.

⑥当定语从句由“代词/数词/名词/形容词比较级、最高级等+of+ which/whom”引导时

China has hundreds of islands off its southeast coast, the largest of which is Taiwan.

The old man has three children, two of whom are college students.

l       怎样选择关系代词或关系副词

引导定语从句的词有关系代词that、which、who、whom、whose、as和关系副词when、where、why。依据先行词在从句中所作的成分而决定。如作主语、宾语、表语或定语，选关系代词，如作状语，择选关系副词。

1．  which与that。

1）that一般不用于非限制性定语从句。

2）当先行词是不定代词时（all、something、everything、little、much等）。

3）当先行词被形容词最高级或first、last、next等修饰时。

4）当先行词被the very、the same、the only修饰时。

5）当先行词在定语从句中作表语时。e.g. China is not the country (that) it was.

6）避免重复时。   e.g. Which is the car that overtook（超车） us yesterday?

但在下列情况下，只能用which，不能用that:

1)      在介词后。2) 非限制性定语从句中。 3) 代替前面整个句子的意思。

e.g. Xiao Ming lost his bag, which made his mother very angry.

2．  that与who。

1)      that一般不用于非限制定语从句中。   2) 当先行词被“same”修饰时。

e.g. She is the same teacher that was praised the other day.

2)      当先行词是who。  e.g. Who that breaks the laws will be punished.

3)      当先行词一个指人，另一个指物时。

4)      当先行词在定语从句中作表语时。  e.g. Tom is not the boy (that) he was.

   但当先行词是人称代词时，关系代词只能who用不能用that。

e.g. You, who know me, should trust me.  你是知道我的，应该相信我。

3．  whom（宾格），在从句中作宾语。

4．  whose（所有格），在从句中作定语，既可修饰人，也可修饰物。

e.g. I live in a room whose window faces south. / I live in a room, the window of which faces south.

5．  关系词与连词as。

1）  用于the same … as …、such … as …、so … as …、as … as …等句型中，as引导的定语从句常采用省略形式。

e.g. I’d like to use the same tool as we used yesterday. / He lifted so heavy a stone as no one else can lift.

   You may take as many magazines as you want.

   在“the same …”后也可以用that引导定语从句，但意义有所不同。

   that引出的从句，指的是与先行词同一的事物，而as引导的从句是与先行词相似的同类事物。

【比较】I’d like to use the same tool that we used yesterday.（指昨天用过的那把）

        I’d like to use the same tool as we used yesterday.（指与昨天用过的那把相同）

2）  as还可以修饰一个主句。这时与which引导的从句不同之处在于：

   as引导的从句可置于主句前，也可置于主句后，而which引导的从句只能置于主句后。which连接的主从句，它们之间含有因果关系。

6．  when修饰表示时间的名词（time, hour, month, year等）。

e.g. The first time (that) I came to Beijing was in 1989.

7．  where修饰表示地点的名词。

     总之，在考虑选用定语从句的关系代时，除考虑其修饰的是什么词外，还必须考虑在从句中的成分，尤其是在修饰表示时间或地点的名词时。

8．  why表示原因。  e.g. Do you know the reason why he is absent today?

l       先行词是时间或地点时

【例1】  I live in Beijing, where is the capital of China.   (NMET97)

     此处引导词在从句中作主语，代指Beijing，只能用关系代词that或which。

【例2】  I also enjoyed the evenings when we spent together.   (NMET95)

先行词为时间名词时，从句中的关系词可能是when也可能是that或which，这取决于关系词在从句中担当的成分。如果关系词在从句中作主语、宾语，只能用关系代词that或which；如果关系词在从句中作表语、状语则用关系副词when。此处引导词在从句中作spend的宾语，代指evenings，只能用关系代词that或which。