定语从句关系代词的用法:定语从句讲解
时间：2019-05-04 03:26:30 来源：雅意学习网 本文已影响 人 
在英语新课改中，第一个语法重点就是定语从句。在学生接触定语从句之前有必要让学生学习英语的基本五种句型，用最简单的句型让学生知道主语、谓语、宾语、定语的位置。在学生了解这些句型以后再来解释什么是定语从句，这样学生才会易懂。
由一个句子来修饰名词或代词的句子就是定语从句。被定语从句修饰的词叫做先行词。引导定语从句有关系代词that、which、who、whom、whose和关系副词when、where、why.
一． 关系代词的功能
关系代词引导定语从句时，在先行词和定语之间起一个连接的作用。关系代词要在句子中充当一定的成分，关系代词在句中充当主语、宾语、定语的成分。
1.that 和which的用法：
A plane is a machine that can fly.
They needed a plant which didn’t need as much water as rice.
教师在讲解时首先让学生把主从句分开，让学生自己观察从句缺哪种成分，第一句缺主语，第二句也是缺主语。学生就可以归纳：that、which 修饰前面的先行词在从句中可以充当主语的成分。多举例让学生自己找出共性，自己归纳关系代词的用法。
The noodles (that) I cooked were delicious.
Today, fruit trees which once grew only in China can now be found in many parts of the world.
The train that ( which ) has just left is for Shanghai.
All the people that come from the country work much harder.
归纳：that、 which 修饰前面的先行词在从句中不仅充当主语的成分还充当宾语的成分，但是充当宾语时that 、which 可以省略。that 修饰的先行词可以指物也可以指人，which 只用来指物。当that 和which 都是指物，而且充当主语或宾语时，两者可以互换。
2. who、 whom的用法
In the beginning, people who bought the tomato often got angry.
The person (whom) you should write to is Mr. Ball.
归纳：who和whom 修饰的先行词都是指人，who 在句中充当主语，而whom 在句中充当宾语。
3.whose 的用法：
I have a friend whose father is a mayor.
In our class , we have some students whose families are not in Wuhan.
归纳：whose 修饰的先行词可以是人也可以是物，在句中充当的是定语的成分，相当于of which.
二． 区分that 和which 的用法：
1.用which 不用that
The train that ( which ) has just left is for Shanghai
Football, which is an interesting game, is played all over the world.
Language is the most important tool without which people can"t communicate with each other.
归纳：先行词是物时，且充当主语和宾语两者可以互换。但是在引导非限制性定语从句只能用which,前面有介词时也只能用which.
2.用that，不用which的情况
To get the job started, all that I need is your permission.
The first thing that should be done is to get some food.
Those are the very words that he used.
They were talking about the persons and things that they saw in the factory.
China is not the country that it was.
Which is the car that was made in Beijing?
I don"t like the way (that) you speak to her.
归纳：当先行词是all, everything, nothing, something, anything, little等不定代词时。当先行词被形容词最高级或序数词修饰时。当先行词有the very，the only，the same等修饰时。当先行词是一个既指人又指物的并列词组时。当关系代词在定语从句中作表语时。当要避免与疑问词which重复时。当先行词为the way, the time, the period等时，关系代词常用that，但通常被省略。
巧记that和which的区别：
that，which可互换，下列请况勿照办；
that情况比较多，不妨对你说一说；
不定代词这路货，全用that准没错；
先行词前被限制，千万不要用which；
要用which别着急，介词提前逗隔离。
在学习定语从句时，要会划分句子成分，要考虑先行词是人还是物，然后再看句子缺什么成分选择相应的关系代词。多记、多练是学好定语从句的最基本方法。
