定语从句一．基础概念1. 英语的三大类从句：●定语从句：定语可以有形容词，名词，代词，数词，分词，副词，不定式以及介词短语等来担任，也可以有一个句子来担任。

担任定语功能的句子成为定语从句。

定语从句在句中的作用相当于形容词，故又称为形容词性从句。

●名词性从句：在句中起名词作用的句子叫名词性从句。

名词性从句的功能相当于名词词组，它在复合句中能担任主语,宾语，表语，同位语等，因此根据它在句中的不同语法功能，名词性从句又可分别被称为主语从句，宾语从句，表语从句，同位语从句。

●状语从句：在主从复合句中修饰主句中的动词，形容词，副词等的从句叫状语从句。

功能与副词相近，故又称为副词性从句。

一般分为时间，地点，原因，目的，结果，条件，让步，比较，方式等。

2．定语从句所修饰的词叫先行词；连接先行词与从句的词叫关系词。

关系词不仅在先行词与定语从句之间起连接作用，而且作从句中的一个成分。

3.关系词分为●关系代词：who，whom，which，that，as，whose●关系副词：when，where，why二．关系代词的用法：关系代词指代的是先行词，在定语从句中作主语，宾语，表语等。

作宾语时，口语可省略；如果关系代词作介词的宾语且介词提到关系代词的前面时，关系代词不能省略。

1. who，whom 的用法二者都用于指人，who作主语，宾语，whom作宾语，who可替换whom。

eg. He is the man who lives next door.Some people who are successful language learners often succeed in other fields.I happened to meet the professor who/whom I got to know at the party in the shopping center yesterday.注意：在从句中作介词的宾语且直接跟在介词后时，只能用whom，不能用who。

Yesterday I came across the man about whom you talked last night.2. whose 的用法Whose一般指人，但有时也指物，在定语从句中作宾语。

eg. Do you know the girl whose Japanese is excellent?He is the man whose car was stolen last night.Please pass me the book whose cover is green. = Please me the book the cover of which is green.3. which 的用法which 一般指物，在定语从句中作主语，宾语，偶尔作定语。

eg. The train which has just left is for Shenzhen.The river which runs through the center of the city brings us lots of pleasures. 4. that 的用法that 即可指人也可指物，指人时可与who，whom 互换，指物时可与which互换。

在定语从句中可作主语，宾语，表语。

作宾语时可以省略。

eg. Jack is no longer the person that/who/whom I met five years ago.The package which/that you are carrying is about to come unwrapped.你拿的包裹快散了。

5. as 的用法as 引导定语从句主要用于两种情况：一种是限制性定语从句有so，such或the same 修饰；一种是先行词是整个主句的非限制性定语从句，在句中作主语，宾语，它引导的从句可以位于主句前，也可位于主句后，还可以位于主句中间。

eg. You can take as many books as you need. (先行词有as修饰，第二个as是关系代词作need 的宾语)I haven’t so much money as you want.Jeffery is not such an intelligent person as you think.Such people as have made great contributions to the world should be greatly respected. (as 作主语)He is a great hero, as is describe in the report.She is a famous star, as we know.As we had expected, the plan worked out very well.She, as we know , can speak three foreign languages.三. 关系副词的用法1. whenwhen 指时间，在从句中作时间状语。

它的先行词通常为time，day，morning，night，week，year等表示时间的名词。

有时when也和部分介词一起引导定语从句。

eg. I still remember the time when I first traveled by plane.She went to Japan two years ago, since when I haven’t heard from her.2. wherewhere 指地点，在句中作地点状语。

它的先行词通常为place，spot，street，house，city，room，country等表示地点的名词。

where引导的定语从句还可以放在from后。

注意：situation，case，circumstance，state，scene，extent，stage，degree等表示“情形，情况，场合，火候” 的表示抽象地点，用where。

eg. This is the mountain village where I stayed last year.Keep the books in a place where you can find them easily.He did all his research in the room where he lived.The little boy hid himself behind the door, from where he could see his mum enter the room.3. whywhy 指原因或理由，它的先行词只有reason, 在定语从句中作原因状语。

eg. Is this the reason why she refused our offer.I don’t want to listen to any reason why you were absent.四. 限制性定语从句和非限制性定语从句1.限制性定语从句用来修饰和限定先行词，与先行词间的关系非常密切，不用逗号和主句隔开。

它所修饰的先行词代表一个（些）或一类特定的人或物，说明先行词的性质，身份，特征等状况，若去掉，则意思含混不清。

eg. A doctor is a person who cares patients.This is the house which I bought last year.2. 非限制性定语从句，只对先行词作些附加说明，即使去掉主句的意思依然清楚。

它与主句之间通常用逗号隔开。

翻译时常常不译作定语，而是译成与主句并列的句子。

（that不能引导非限制性定语从句）eg. He lives in Beijing, which is about five hour’s ride from here.My house, which I bought last year, has got a lovely garden.This novel, which I have read three times, is very touching.This note was left by Tom, who was here a moment ago.3. 运用非限制性定语从句的情况五. 应用定语从句的注意事项1. 宜用that不宜用which的情况当先行词是all，little，few，much，something，anything，everything，nothing，none，some等不定代词时。

eg. He did everything that he could to help us.All that can be done has been done.先行词被all, every, no, some, any, little, much, the only, the very, the right, the last, few, just等修饰时。

eg. All the things we can do is to give you some advice.Music is the only thing that interests me.This is the very book that I want.先行词是序数词或形容词最高级或被序数词，形容词最高级修饰时。

eg. This is the most interesting book that I have ever read.When people talked about Hangzhou, the first thing that comes to mind is the West Lake.当先行词既有人又有物时。

eg. The guests spoke highly of the children and their performances that they saw at the children’s Palace.当主句是以which开头的特殊疑问句时。

eg. Which of us that knows something about physics cannot join electric wires?2. 宜用which不用that的情况关系代词前有介词时。

eg. The house in which I used to live has become a shoe shop.The pen with which you are writing is Jeff’s.在非限制性定语从句中。