一、定语从句

1．定语从句三步：第一找出先行词；第二看先行词在定语从句中的语法功能（做主语、宾语或状语）；第三选择合适的关联词。

2．定语从句在选择关联词that 与which时，经常轻易出错，所以应记住什么时候只能用that，什么时候只能用which.

（1）．只能用 that 的情况归纳4种：即先得词被序数词最高级修饰过；先行词为all 、everything、nothing等不定代词；先行词同时是人和物并列时；最后先行词分别被the only 、the very the same、the last 修饰。请看下列四组例句，注重其先行词：

①．The first thing that we should do is to work out a plan .

②．I t almost seemed as if the good man were trying to teach us all that he knew at this lesson .

③．Later my father and Mr. Crosset talked for about half an four of things and persons that they remembered in school.

④．This is the very dictionary that I want to find .

（2）．只用which is 情况有两种情况：一是非限制性定语从句，关联词要用which；二是做介词宾语时只能用which。请看下列两组例句：

I said nothing , which made him more angry .

I have the book about which you are talking .

三、在定语从句的非限制性定语中，which 和as 是轻易混淆的。在很多情况下两者兼可互换，但在下列情况中不可互换：

1、通常As 可以放在整句的句首，而which，只能在逗号之后，as 本身含有“正如”，as 在定语从句中既可是主语也可做宾语

As appear from her paper ,she has read widely in Romantic literature.

She is remarkable, as I have told you .

2、 which 在做非限制性定语从句关联词时可以无明确先行词，指前句整个的意思，如：She has married again, which surprises us .

四、在定语从句中，许多人往往分不清all that 和what, what 实际上只引导名词性从句，它相当于all that两个字，例如：

All that I know is that he has made up his mind to heave the country for a new place.

= what I know is that ……

定语从句

知识要点：

一、限定性定语从句：

种类

先行词

关联词

例句

说明

定

语

从

句

（人）在从句中做主语或宾语

物

在从句中做主语或宾语

who

which

This is the doctor who saved the boy’s life .

这就是救了孩子生命的医生。

She is the new student whom I want to introduce to you .

她就是我要介绍给你的新学生

Please pass me the book which is lying on the table.

请递给我摆在桌上的那本书。

The novel which Tom bought is very interesting.

汤姆买的小说很有意思。

Can you lend me the magazine about which you talked yesterday?

你能把昨天谈到的那本杂志借给我吗？

who在从句中做主语

whom在从句中做宾语，口语中who可以代替whom，也可以被省去，但做介词宾语时只能用whom

which在从句中做主语。

which充当宾语时可以省去。

which做介词宾语不可省