定语从句高中英语语法
一、定语从句的引导词
1、一共有9个：who, whom , whose, that, which, when,where, why, as
与名词从句相比：定从不能由what和how引导;which的含义改变;定从内部的介词可以放引导词前。
2、引导词的功能有哪些?
(1)引导定语从句
(2)代替先行词在定语从句中充当一个成分。(先行词在从句中不再出现)
二、定语从句的关键
1、首先，要能判断出该从句是什么从句：
(1)放句首没有用逗号分开的，一般是主语从句，也有可能是状语从句，但从句结束后若有体现时态变化的动词，则一定是主语从句。
(2)放及物动词后，若及物动词不是被动语态，后面一定是宾语从句;若该及物动词是被动语态，后面一般是主语从句(It+ is + adj/n./done+that/whether/when…)或状语从句。
(3)放be动词后，后面一定是表语从句，但 “It is/was + 从句(被强调成分) + that”是强调句(强调句中“非谓语”)。
(4)放名词后，一般是定语从句，但若该名词有“内涵/内容”(fact/truth/news/information/ problem/suggestion)， 则很可能是同位语从句。
(5)用逗号分开的从句，一般是状语从句或 as/which引导的定语从句，也要注意用放在句中用逗号分开的“插入语”(however, for example,believe it or not等)。
2、其次，判断出是定语从句后可以用“三个优先”法做题：
(1)优先选择含whose的选项，能与空格后的名词构成“某人的某物”搭配，一般就是答案;
(2)优先选择含介词的选项，然后看该介词与从句中的谓语是否能构成符合逻辑的搭配;
(3)用逗号分开的定从，优先考虑as和which,若该空能翻译为“一件事”而从句意思是通顺的，则放句首就用as,句末用which(若该空能翻译为“如同”“像…一样”则应用as)
3、再次,做定语从句题可以用“三问法”来检测是否出错：
(1)先行词本身是否为特殊的词?
way+ in which/that/省略
指物的不定代词：anything, one, some,many, a lot, all, both, that等 + that
指人的不定代词或数词：one, those, anyone, two等 + who
既有人又有物： + that
“抽象的地点”condition, situation,case, point + where
“抽象的时间”one’s stay/visit + when
在特定语境中可以作“地点/位置”理解的词：trousers/ sleeves + where
(2)先行词前面有无特殊的词?
有不定代词修饰：all/every/little/much+ …+ that
有最高级/序数词修饰：the best/second … + that
有just the/ the very/ the only/ the last等修饰：+ that
有who/which疑问词：+ that(避免重复)
有the same/ such/ as修饰：一般+ as
(注意： ①第一个as是否为一个以as结尾的搭配，如regard…as;
②区分such…as(定从)与such …that“如此…以至于”)
(3)先行词在定语从句中充当什么成分?
注意：从句中spend后的“时间”，以及visit后的“地点”，不是状语，而是宾语，应该用不定代词
4、只能用that引导定语从句有哪些情况?
先行词前为all, everything, nothing,something, anything, little, much等不定代词时;
先行词前有：all, every, no, some, any,little, much, few等不定代词修饰时;
先行词被序数词修饰时;
先行词被形容词最高级修饰时;
先行词前only, just, very, last有等修饰时;
先行词是表示人和物混杂的'两个名词时;
主句是以who, which,开头的疑问句或先行词是疑问代词时;
在修饰时间、地点等先行词时，只有用that代替when, where等引导词;
【例】I'll never forget the Sunday (that) you first arrived.
Do you know anywhere (that) I can get a drink ?
先行词为reason, way (意为“方法”)时，常用that 代替why,which, in which，也可省略。
引导词在定语从句中作表语时，多用that引导。
先行词是主句表语时;
【例】It is a dictionary that will help you a lot.
当主语以there be 开头时;
当先行词是数词时;
同一个复合句里有两个定语从句，一个用which，另一个通常用that。
5、reason后面用什么引导?way 后面用什么引导?
reason后面的定语从句用why引导。
way 后面定语从句用in which 或 that引导that可以省略。
6、when引导的定语从句等于什么引导的定语从句?
when引导的定语从句等于介词+ which引导的定语从句。
7、where 引导的定语从句等于什么引导的定语从句?
where 引导的定语从句等于介词+which引导的定语从句。
★8、one of 和 the (only) one of引导的定语从句在主谓一致问题上应注意什么?
前者引导的定语从句谓语动词用复数;后者用单数。
9、限制性定语从句与非限制性定语从句有和区别?
限制性定语从句是主句不可缺少的一个部分，缺少后主句意思不完整。非限制性定语从句是对主句的进一步说明，不要从句对主句意义无多大影响;非限制性定语从句前后有逗号隔开。而且非限制性定语从句中不能用that。
10、as 和which引导的非限制性定语从句在用法上有什么区别?
as和 which 都可以引导非限制性定语从句.都可以代替主句中的整个内容或某一成分。
as 引导的非限制性定语从句可以位于句首，并常和know, see, expect等词连用，意为：“正如……”，而which不能位于句首。
11、as 可以用于哪些结构中引导定语从句?
such... as; the same... as; so ...as..
12、the same…as和 the same…that 引导的定语从句如何区别?
the same…as 引导的定语从句指的是相同事物，强调同类。
the same…that引导的定语从句指的是同一物。
13、such…as …和 such…that…如何区分?
such…as…引导的是定语从句，as必须代替先行词在其引导的从句中充当成分。
such…that…引导的从句是状语从句，that只是引导从句并不在其引导的从句中充当成分，在选择填空首先看从句中是否缺句子成分，如果缺成分就要考虑是定语从句;如果不缺成分就要考虑是状语成分。
★14、whose 引导定语从句有那些注意点?
whose 作定语，后面跟名词。一般有三种表示形式：
【例】This is the dictionary whose cover has come off.
= This is the dictionary the cover of which has come off.
= This is the dictionary of which the cover has come off.
★★★15、 “介词 + 关系词” 开头的定语从句有哪几种情况?
注意：引导定从的介词后不能加who/that
(1)先行词在从句中做状语，用来替换when/where/why的：in/on/from/for/in front of + which/whom:
(2)“of所有格”： the+名词+ of + which/whom; of + which/whom +… the+名词
(3)“某个范围中的多少”： some/both/the former + of + which/whom; of + which/whom … some…
(4)偶尔可用“介词+ whose”和“介词+where”
三、关系代词引导的定语从句
关系代词所代替的先行词是人或物的名词或代词，并在句中充当主语、宾语、定语等成分。关系代词在定语从句中作主语时，从句谓语动词的人称和数要和先行词保持一致。
1、who指人，在从句中做主语
The boys who are playing football are from Class One.
2、whom指人，在定语从句中充当宾语，常可省略。
Mr. Liu is the person (whom)you talked about on the bus.
【注意】关系代词whom在口语和非正式语体中常用who代替，可省略。
The man who/whom you met just now is my friend.
3、which指物，在定语从句中做主语或者宾语，做宾语时可省略
Football is a game which is liked by most boys.
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。
The number of the people that/who come to visit the city each year rises one million.
5、whose通常指人，也可指物，在定语从句中做定语
He has a friend whose father is a doctor.
whose指物时，常用以下结构来代替：
The classroom whose door is broken will soon be repaired.
=The classroom of which the door is broken will soon be repaired.
Do you like the book whose cover is yellow?
=Do you like the book the color of which is yellow?
(注意：the + 名词 + of which/whom常考!)
四、介词+关系代词whom/which引导的定语从句(重点)
关系代词在定语从句中做介词宾语时，从句常由介词+关系代词引导：
The school (that/which) he once studied in is very famous.
=The school in which he once studied is very famous.
【注意】
1、含有介词的动词短语一般不拆开使用，如：look for, look after, take care of等
(1)This is the watch which/that I am lookingfor.(T)
(2)This is the watch for which I amlooking. (F)
2、若介词放在关系代词前，关系代词指人时用whom，不可用who或者that;指物时用which，不能用that;关系代词是所有格时用whose
(1)The man with whom you talked is my friend.(T)
(2)The man who/that you talked with is my friend.(F)
3、“介词+关系代词”前可有some, any, none, both, all, neither, most,each, few等代词或者数词，构成some of which/whom等类似结构引导的定语从句。(重点：常考!)
(1)He loved his parents deeply, of whom both are very kind to him.
(2)In the basket there are quite many apples, some of which have gone bad.
(3)There are forty students in our class in all, most of whom are from big cities.
在特定语境中，可以用“介词+ whose/where”引导定语从句
The boss in whose department Ms King once worked is a kind man.
五、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
when=during/ on/ in/ ... which (介词同先行词搭配)
(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
where=in/ at/ on/ ... which (介词同先行词搭配)
(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，此时先行词常为reason。可变为for which(常考!)
why=for which
(1)Please tell me the reason why you missed the plane.
(2)I don’t know the reason why he looks unhappy today.
【注意】关系副词引导的从句可以由“介词+关系代词”引导的从句替换
(1)The reason why/ for which he refused the invitation is not clear.
(2)From the year when/in which he was going to school he began to know what he wanted when he grew up.
(3)Great changes have taken place in thecity in which/where I was born.
