英语基础语法：定语从句

定语从句（Attributive Clauses）在句中做定语，修饰一个名词或代词，被修饰的名词 , 词组或代词即先行词。定语从句通常出现在先行词之后，由关系词（关系代词或关系副词）引出。

关系代词有：who, whom, whose, that, which 等。

关系副词有：when, where, why 等。

1、关系代词引导的定语从句

关系代词所代替的先行词是人或物的名词或代词，并在句中充当主语、宾语、定语等成分。关系代词在定语从句中作主语时，从句谓语动词的人称和数要和先行词保持一致。

1）who, whom, that

这些词代替的先行词是人的名词或代词，在从句中所起作用如下：

Is he the man who/that wants to see you?

他就是你想见的人吗？（who/that 在从句中作主语）

He is the man whom/ that I saw yesterday.

他就是我昨天见的那个人。（whom/that 在从句中作宾语）

2）Whose 用来指人或物，（只用作定语 , 若指物，它还可以同 of which 互换），例如：

They rushed over to help the man whose car had broken down. 那人车坏了，大家都跑过去帮忙。

Please pass me the book whose (of which) cover is green. 请递给我那本绿皮的书。

3）which, that

它们所代替的先行词是事物的名词或代词，在从句中可作主语、宾语等，例如：

A prosperity which / that had never been seen before appears in the countryside. 农村出现了前所未有的繁荣。（which / that 在句中作宾语）

The package (which / that) you are carrying is about to come unwrapped. 你拿的包快散了。 (which / that 在句中作宾语）

2 、关系副词引导的定语从句

关系副词可代替的先行词是时间、地点或理由的名词，在从句中作状语。

1）when, where, why

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？

2）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。

3、判断关系代词与关系副词

方法一：用关系代词，还是关系副词完全取决于从句中的谓语动词。及物动词后面无宾语，就必须要求用关系代词；而不及物动词则要求用关系副词。例如：

This is the mountain village where I stayed last year.

I'll never forget the days when I worked together with you.

判断改错

（错）This is the mountain village where I visited last year.

（错）I will never forget the days when I spent in the countryside.

（对）This is the mountain village (which) I visited last year.

（对）I'll never forget the days (which) I spent in the countryside.

习惯上总把表地点或时间的名词与关系副词 where, when 联系在一起。此两题错在关系词的误用上。

方法二：准确判断先行词在定语从句中的成分 ( 主、谓、宾、定、状 ) ，也能正确选择出关系代词 / 关系副词。

例 1. Is this museum ___ you visited a few days age?

A. where B. that C. on which D. the one

例 2. Is this the museum ____ the exhibition was held.

A. where B. that C. on which D. the one

答案：例 1 D ，例 2 A

例 1 变为肯定句：This museum is ___ you visited a few days ago.

例 2 变为肯定句：This is the museum ___ the exhibition was held.

在句 1 中，所缺部分为宾语，而 where, that, on which 都不能起到宾语的作用，只有 the one 既做了主句的表语，又可做从句的宾语，可以省略关系代词，所以应选 D 。

而句 2 中 , 主、谓、宾俱全，从句部分为句子的状语表地点，既可用副词 where ，又因 in the museum 词组，可用介词 in + which 引导地点状语。而此题中，介词 on 用的不对，所以选 A 。

关系词的选择依据在从句中所做的成分，先行词在从句中做主、定、宾语时，选择关系代词 (who, whom, that, which, whose) ；先行词在从句中做状语时，应选择关系副词 ( where 地点状语，when 时间状语，why 原因状语 ) 。

4、限制性和非限制性定语从句

1) 定语从句有限制性和非限制性两种。限制性定语从句是先行词不可缺少的部分，去掉它主句意思往往不明确；非限制性定语从句是先行词的附加说明，去掉了也不会影响主句的意思，它与主句之间通常用逗号分开，例如：

This is the house which we bought last month. 这是我们上个月买的那幢房子。（限制性）

The house, which we bought last month, is very nice. 这幢房子很漂亮，是我们上个月买的。（非限制性）

2) 当先行词是专有名词或物主代词和指示代词所修饰时，其后的定语从句通常是非限制性的，例如：

Charles Smith, who was my former teacher, retired last year. 查理 · 史密斯去年退休了，他曾经是我的老师。

My house, which I bought last year, has got a lovely garden. 我去年买的的那幢房子带着个漂亮的花园。

This novel, which I have read three times, is very touching. 这本小说很动人，我已经读了三遍。

3) 非限制性定语从句还能将整个主句作为先行词 , 对其进行修饰 , 这时从句谓语动词要用第三人称单数，例如：

He seems not to have grasped what I meant, which greatly upsets me. 他似乎没抓住我的意思，这使我心烦。

Liquid water changes to vapor, which is called evaporation. 液态水变为蒸汽，这就叫做蒸发。

说明：关系代词 that 和关系副词 why 不能引导非限制性定语从句。

5 、介词 + 关系词

1）介词后面的关系词不能省略。

2）that 前不能有介词。

3）某些在从句中充当时间，地点或原因状语的 " 介词 + 关系词 " 结构可以同关系副词 when 和 where 互换。

This is the house in which I lived two years ago.

This is the house where I lived two years ago.

Do you remember the day on which you joined our club?

Do you remember the day when you joined our club?

6 、as, which 非限定性定语从句

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。

As we know, smoking is harmful to one's health.

The sun heats the earth, which is very important to us.

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 …… 。

I have got into the same trouble as he (has).

例 2. as 可引导非限制性从句，常带有 ' 正如 ' 。

As we know, smoking is harmful to one's health.

As is know, 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。

7、先行词和关系词二合一

1)Whoever spits in public will be punished here.

(Whoever 可以用 anyone who 代替 )

2)The parents will use what they have to send their son to technical school.

(what 可以用 all that 代替 )

8、what/whatever; that/what; who/whoever

1) what = the thing which ；whatever = anything

What you want has been sent here.

Whatever you want makes no difference to me.

2) who= the person that whoever= anyone who

（错） Who breaks the law will be punished.

（错） Whoever robbed the bank is not clear.

（对） Whoever breaks the law will be punished.

（对） Who robbed the bank is not clear.

3) that 和 what

当 that 引导定语从句时，通常用作关系代词，而引导名词性从句时，是个不充当任何成分的连接词。宾语从句和表语从句中的 that 常可省略。What 只能引导名词性从句，用作连接代词，作从句的具体成分，且不能省略。

I think (that) you will like the stamps.

What we need is more practice.

9、关系代词 that 的用法

1) 不用 that 的情况

a) 在引导非限定性定语从句时。

(错) The tree, that is four hundred years old, is very famous here.

b) 介词后不能用。

We depend on the land from which we get our food.

We depend on the land that/which we get our food from.

2) 只能用 that 作为定语从句的关系代词的情况

a) 在 there be 句型中，只用 that ，不用 which 。

b) 在不定代词，如：anything, nothing, the one, all, much, few, any, little 等作先行词时，只用 that ，不用 which 。

c) 先行词有 the only, the very 修饰时，只用 that 。　

d) 先行词为序数词、数词、形容词最高级时，只用 that 。 .

e) 先行词既有人，又有物时。

举例：

All that is needed is a supply of oil. 所需的只是供油问题。

Finally, the thief handed everything that he had stolen to the police. 那贼最终把偷的全部东西交给了警察。