文档介绍：定语从句用法
定语从句用法
 
定语从句的有关概念
两种类别----------限制性和非限制性
根据从句与主句的关系是否紧密来区分，定语从句可分为限制性定语从句和非限制性定语从句两大类。
两个重要概念——先drank.
正：The main reason for which he lost his job was that he drank.
正：The main reason that he lost his job was that he drank.
正：The main reason he lost his job was that he drank.
4. How的用法 in which----that----省略不用
关系副词how在定语从句中也是用作状语，表示方式；how引导定语从句时，其先行词只有一个，那就是the way.
五、非限制性定语从句
所谓限制性定语从句，它的作用是对先行词起修饰、限制或确定的作用，若去掉，先行词的意思就不明确，它是不可缺少的一部分，它与先行词的关系密不可分，不可用逗号将其分开。
而非限制性定语从句的作用则只是对先行词起补充说明作用，它是可有可无的，与先行词关系松散，通常用逗号将其分开。因此，有无逗号通常是区分限制性定语从句和非限制性定语从句的重要标志。
从所使用的关系词来看，在限制性定语从句中，that可以代替who, whom和which等，但在非限制性定语从句中不能用that。如：
He changed his mind, which made me very angry. 他改变了主意，这使我很生气。
Then he met Mary, who invited him to a party. 后来他遇到玛丽，玛丽邀请他去参加晚会。
另外，关系副词when和where既可引导限制性定语从句，也可引导非限制性定语从句；但关系副词why和how则只能引导限制性定语从句，不能引导非限制性定语从句。
We’ll put off the picnic until next week, when the weather may be better. 我们将把野餐推迟到下星期，那时天气可能会好一点。
Barbary was working in Aubury, where she went daily in a bus. 巴巴拉在奥伯里工作，每天得坐公共汽车去上班。
以上两句中的关系副词when和where均引导非限制性定语从句。
六 as和which引导的非限制性定语从句
共性：先行词为一件事；
差异：as从句可以在先行词前或后，which从句只能在先行词后
He is a good guy, as we all know.
As we all know, he is a good guy.
He is a good guy, which we all know
七、关系代词还是关系副词
关系词在定语从句用作主语或宾语，则用关系代词；用作状语，则用关系副词。
Don’t forget the time that I’ve told you. 不要忘记我告诉你的时间。
This is the house that he bought yesterday. 这就是他昨天买的那座房子。
：
1) 先行词被形容词最高级修饰时，定语从句只能用that
This is the most interesting story (that) I have ever heard.
2）先行词被序数词修饰时，定语从句只能用that
The children like the second lesson that is about “The Football Match”.
3）先行词被the only，the very 或the same等修饰，定语从句只能用that引导。
It is the only word (that) I know in the passage.
Where is the very book (that) I bought just now?
This is the (same) bicycle (that) I lost.
4）先行词为everything，something，anything，all，none，much，little，few等不定代词时，定语从句只能用that
I want everything (that)