英语“定语从句的用法”教学探索
中图分类号：G424 文献标识码：A 文章编号：1006-4117（2011）09-0288-02
英语多用主从复合句，汉语多用并列句。因此，要想学好英语，掌握从句的用法非常重要。定语从句的用法是英语教学的一个重点，也是英语学习的一个难点，学生们在日常学习和考试中对定语从句的用法也常存有疑问，本文探索了定语从句的教学要点。
定语从句（形容词性从句）：用来修饰、说明主句中某一名词或代词（有时也可说明整个主句或主句中的一部分）而起定语作用的句子叫做定语从句。分为限制性和非限制性定语从句。英语的定语从句通常紧跟在所修饰的名词或代词后，但译成汉语时，则常常把定语从句放在所修饰的词的前面。定语从句所修饰的名词或代词称为“先行词”。
一、关系代词引导的定语从句
（一）关系代词用来指代先行词是人或物的名词或代词，并且作定语从句的一个成分（主语、宾语、定语）。即，关系代词有三个作用：一是引导定语从句；二是指代先行词；三是作定语从句的一个成分（主语、宾语、定语）。
This is the detective who came from London.
The book which I am reading is written by Tomas Hardy.
The desk whose leg is broken is very old.
This is the room that/which Shakespeare was born in.
（二）关系代词在定语从句中作主语时，定语从句的谓语动词与所修饰的词的人称和数要一致
The nurse who is on duty takes care of the patients.
The nurses who are on duty take care of the patients.
Note: the only one of + 复数名词，后接定语从句时，从句里的动词用单数。
作主语时，谓语动词用单数
One of + 复数名词 后接定语从句时 :1、关系代词指of后的复数名词时，从句动词用复数；2、关系代词指one时，从句动词用单数。
He is the only one of the students who has passed CET6.
This is one of the presents which were given to me by my friends.
（三）在限制性定语从句中作及物动词宾语的关系代词常可省略。在非限制性定语从句中，关系代词不能省略，也不能用that
I know the man (whom/that) you met yesterday.
There is no difficulty (which/that) we cannot overcome.
（四）介词 + 关系代词引导定语从句：用whom指人，which指物，不能用that。用哪个介词，要视句子的意思而定
He is a man from whom we should all learn.
This is the laboratory in which he made his experiment.
1、在非限制性定语从句中，of which/whom前可以有数词、名词及all, any, both, few, enough, many, most, none, several, some等；
There are fifty students in the class, sixty percent of whom are boys.
There are about seven million people taking part in the election, most of whom are well educated.
2、在口语中一般都把介词放到从句的后面，这时可以用that，但省略的时候更多一些。
He is a man (whom/that) we should all learn from.
Here is the book (which/that) you have been looking for.
3、像listen to, look at, depend on, pay attention to, take care of等固定短语动词，在定语从句中一般不宜将介词与动词分开。
This is the boy whom she has taken care of.
4、from where为“介词＋关系副词”结构，也可以引导定语从句。
We stood at the top of the hill, from where we can see the town.
（五）that的用法：只用于限制性定语从句中，而不能用于非限制性定语从句中。下列情况习惯用that：
1、当先行词是everything, something, nothing, anything, all, little, few等不定代词时；
Everything (that) he said was funny.
All the people that are present burst into tears.
2、当先行词由序数词，或形容词最高级、以及the only, the very, the last, the same等词修饰时；
This is the shortest road that leads to the station.
This is the very book (that) I want to find.
3、当先行词是并列的“人”和“物”时；
They talked about the persons and things that most impressed them.
The boy and the dog that are in the picture are very lovely.
4、当先行词为who时；
Who that has seen the girl doesn’t love her?
5、以There be开头的句子后的定语从句；
There are three things that made Sydney famous―its beautiful harbor, the Sydney Harbor Bridge and the Sydney Opera House.
6、定语从句中动词是be或there be时，关系代词用that或省略。
John is not the man (that) he was.（不能用who）
（六）关系代词as的用法：as常在such…as和the same…as的结构中引导定语从句
I told him the same story as (或that) you told me.
Such people as you describe are rare nowadays.
（七）which和as都能在引导非限制性定语从句时代表前面整个主句或谓语的意思。区别在于：
1、都可在主系表结构或主谓结构中作主语；
He passed the examination, as/which as natural.
The street was blocked, as/which often happens in rush hours.
2、用作主谓宾或主谓宾宾补的主语时，用which不用as；
He was late again, which made me very angry.
3、关系代词前有（短语）介词时，用which不用as；
He spent most of his time in class teaching dialogues, the object of which was to enable the students to communicate.
4、从句为否定句或否定前缀词时，用which不用as；
He can write a letter, which I cannot.
He has married again, which was unexpected.
5、as有“正如”的意思，which没有；
She is beautiful, as are all her sisters.
The machine went wrong, as everyone had expected.
6、as从句可放句首，which不可。（但含倒装结构的as从句不可放在句首。）
As is known to the world, Mark Twain is a great American writer.
He traveled a great deal, as did most of his friends.
二、关系副词引导的定语从句
表示时间、地点、原因等，在定语从句中作状语，若在定语从句中不是充当状语就不能用。即，关系副词有两个作用：一是引导定语从句；二是作定语从句的状语。（Note:关系代词和关系副词的选择依据：弄清楚引导词在定语从句中作什么成分，作状语的应选用关系副词；作主语，宾语或定语的应选用关系代词。）
1、where（先行词是表示地点的名词）= in which
This is the hospital where Dr. Li worked.
This is a place (that/which) I’ve long wanted to visit.
2、when（先行词是表示时间的名词）= in/on which
It was the year when I began to learn English.
This is the time which I forgot to take down.
但在不少情况下，可以省略when，特别是在某些句型或时间状语中。
In the ten days I was there I often saw her.
3、why（先行词是表示原因的名词reason, cause）= for which
This is the reason (why) I did it.（why也可省略）
The reason why he is late is that he failed to catch the first bus.
Note: reason后的表语从句不能用because引导。
4、way后定语从句的引导词不能用how，要用that或in which，但常省略。
Do you like the way (that/which) she speaks English?
三、限制性定语从句和非限制性定语从句
（一）限制性定语从句：对所修饰的词的词义加以限制，使之表示一个、一些或一类特定的人或物；这类从句不能去掉，是整句中不可缺少的一部分，如果去掉的话，先行词的意义就不可理解或者完全变了样。限制性定语从句一般紧跟先行词，和先行词之间没有逗号分开，讲话时没有停顿，翻译时常译在所修饰的词之前。
This is the bike that I bought yesterday.
A man who doesn’t try to learn from others can’t hope to achieve much.
（二）非限制性定语从句：对所修饰的词只是作一些附加说明，相当于一个插入语，对先行词的含义不起限定作用。可以去掉，去掉后句子的其它部分仍成立。这类从句和句子的其它部分通常用逗号分开，常可译成一个并列句。
She dislikes trains that are dirty.
我不喜欢不干净的火车。（言下之意，喜欢干净的火车）
She dislikes trains, which are dirty.
我不喜欢火车，火车不干净。（不喜欢火车，理由是火车不干净）
四、定语从句与同位语从句的区别
（一）定语从句的引导词that是关系代词，既指代先行词，同时又可以在从句中作某个成分（主语或宾语）；而同位语从句中的that是连词，只起连接主句与从句的作用，不充当从句中任何成分。
（二）定语从句是形容词性的，其功能是修饰先行词，对先行词加以限定，描述其性质或特征；同位语从句是名词性的，其功能是对名词进行补充说明，是解释前面的名词所讲的内容是什么的。
（三）引导定语从句的that有时可省略，但引导同位语从句的that不能省略。
The news that he told me is that Tom would come back next year.
他告诉我的消息是汤姆明年将回来。（第一个that引导的从句是定语从句，that在从句中作宾语）
The news that Tom would come back is told by him.
汤姆将回来的消息是他讲的。（同位语从句，that在句中不作任何成分）
作者单位：南阳医学高等专科学校公共教学部
