定语从句(详解及关键注意事项)

定语从句

1、定语可以由形容词，名词，代词，数词，分词，副词，不定式以及介词短语来担任，也可以由一个句子来担任．定语从句是由关系代词或关系副词引导的从句，其作用是作定语修饰主句的某个名词性成分，相当于形容词，所以又称为形容词性从句．

2、定语从句用来修饰名词，代词或整个主句．

3、定语从句分为限定性和非限定性从句两种。

4、定语从句存在的条件:先行词+关系词+从句

5、定语从句的构成步骤：

1）找出先行词

a．确定从句中关系代词的人称和数。

b．确定定语从句的位置（一般定语从句都紧跟在先行词后）

2）确定关系代词在从句中所担当的成分，以确定关系代词的格。

3）确定从句时态，根据实际情况确定定语从句的时态（它的时态和语态都不受主句的限制）。（一）定语从句及相关术语

1、定语从句：修饰一个名词或代词的从句称为定语从句，一般紧跟在它所修饰的先行词后面。

2、关系词：引导定语从句的关联词成为关系词关系词有关系代词和关系副词。关系代词有that, which, who, whom, whose, as等；关系副词有where, when, why等。

关系词常有3个作用：1. 引导定语从句 2. 代替先行词 3. 在定语从句中担当一个成分

（二）关系代词引导的定语从句

1.who指人，在从句中做主语

(1) The boys who are playing football are from Class One.

(2) Yesterday I helped an old man who lost his way.

注意：当关系代词在定语从句中作主语时，谓语动词应与先行词的人称和数保持一致。

(1) I, who am your best friend, will do all that I can to help you.

(2) The family, who are fond of music, go to the concert once a month.

(3) He is one of the boys in our class who speak English well.

（one of +复数名词+关系代词引导的定语从句谓语动词用复数形式）

(4) He is the only one of the boys in our class who speaks English well.

the (only；very；right) one of +复数名词+关系代词引导的定语从句谓语动词用单数形式）

2. whom指人，在定语从句中充当动词或介词的宾语，常可省略。

(1) Mr. Liu is the person whom you talked about on the bus.（whom 作介词about的宾语）

(2) Mr. Ling is just the boy whom I want to see. （whom作see的宾语）

注意：关系代词whom在口语和非正式语体中常用who或that代替，可省略，比如:

Do you know the boy whom/who/that my mother is talking to?

注意：如果介词后面只能用whom，例如：Do you know the boy to whom my mother is talking?

3.which指物，在定语从句中做主语或者宾语，做宾语时可省略

(1) Football is a game which is liked by most boys.

(2) This is the pen (which) he bought yesterday.

4. that指人时，相当于who或者whom；指物时，相当于which。

在定语从句中做主语或者宾语，做宾语时可省略。

(1) The number of the people that/who come to visit the city each year rises one million.

(2) Where is the man that/whom I saw this morning?

5. whose通常指人，也可指物，在定语从句中做定语

(1) He has a friend whose father is a doctor.

(2) I once lived in a house whose roof has fallen in.

whose指物时，常用以下结构来代替

(3) The classroom whose door is broken will soon be repaired.

(4) The classroom the door of which is broken will soon be repaired.

(5) Do you like the book whose cover is yellow?

(6) Do you like the book the color of which is yellow?

6．but作关系词只能引导限制性定语从句，同具有否定意思的主句连用，相当于that…not, who…not或which…not。

(1) There is not a single student in my class but would like to study more. （but = who…not ）

(2) There are very few but are against war （but = who…not）

（四）关系副词引导的定语从句

1. when指时间，在定语从句中做时间状语

(1) I still remember the day when I first came to the school.

(2) The time when we got together finally came.

2. where指地点，在定语从句中做地点状语

(1) Shanghai is the city where I was born.

(2) The house where I lived ten years ago has been pulled down.

3. why指原因，在定语从句中做原因状语

(1) Please tell me the reason why you missed the plane.

(2) I don’t know the reason why he looks unhappy today.