定语从句高考知识点

介词+关系词
1）介词后面的关系词不能省略。
2）that前不能有介词。
3） 某些在从句中充当时间，地点或原因状语的“介词+关系词”结构可以同关系副词when 和where 互换。
This is the house in which I lived two years ago.
This is the house where I lived two years ago.
Do you remember the day on which you joined our club？
Do you remember the day when you joined our club？
先行词和关系词二合一
1)Whoever spits in public will be punished here.
(Whoever 可以用 anyone who 代替)
2)The parents will use what they have to send their son to technical school.
(what 可以用all that代替)
as， which 非限定性定语从句
由as， which 引导的非限定性定语从句，as和which可代整个主句，相当于and this或and that。As一般放在句首，which在句中。
As we know， smoking is harmful to one's health.
The sun heats the earth， which is very important to us.
典型例题
1）Alice received an invitation from her boss， ___came as a surprise.
A. it　 B. that　 C. which　　D. he
答案C. 此为非限定性从句，不能用 that修饰，而用which.，it 和he 都使后句成为句子，两个独立的句子不能单以逗号连接。况且选he句意不通。
2）The weather turned out to be very good， ___ was more than we could expect.
A. what　B. which　C. that　D. it
答案B。which可代替句子，用于非限定性定语从句，而what不可。That 不能用于非限定性定语从句，it不为连词，使由逗号连接的两个句子并在一起在英语语法上行不通。
3）It rained hard yesterday， ____ prevented me from going to the park..
A. that　B. which　　C. as　 D. it
答案B.
as 和which在引导非限制性定语从句时，这两个关系代词都指主句所表达的整个意思，且在定语从句中都可以作主语和宾语。但不同之处主要有两点：
(1） as 引导的定语从句可置于句首，而which不可。
(2） as 代表前面的整个主句并在从句中作主语时，从句中的谓语必须是系动词；若为行为动词，则从句中的关系代词只能用which.。
在本题中，prevent由于是行为动词，所以正确选项应为B。
As 的用法
例1. the same… as；such…as 中的as 是一种固定结构， 和……一样……。
I have got into the same trouble as he (has).
例2. as可引导非限制性从句，常带有'正如'。
As we know， smoking is harmful to one's health.
As is know， smoking is harmful to one's health.
As是关系代词。例1中的as作know的宾语；例2中，它充当从句的主语，谓语动词know要用被动式。
关系代词that 的用法
1）不用that的情况
a) 在引导非限定性定语从句时。
(错)　The tree， that is four hundred years old， is very famous here.
b) 介词后不能用。
We depend on the land from which we get our food.
We depend on the land that/which we get our food from.
2) 只能用that作为定语从句的关系代词的情况
a)　在there be 句型中，只用that，不用which。
b)　在不定代词，如：anything， nothing， the one， all， much， few， any， little等作先行词时，只用that，不用which。
c)　先行词有the only， the very修饰时，只用that。
d)　先行词为序数词、数词、形容词最高级时，只用that。.
e)　先行词既有人，又有物时。
举例：
All that is needed is a supply of oil.
所需的只是供油问题。
Finally， the thief handed everything that he had stolen to the police.
那贼最终把偷的全部东西交给了警察。
难点分析
（一）限制性定语从句只能用that的几种情况
1．当先行词是anything， everything， nothing (something 除外)， few， all， none， little， some等代词时，或者是由every， any， all， some， no， little， few， much等修饰时
(1) Have you taken down everything that Mr. Li has said？
(2) There seems to be nothing that seems impossible for him in the world.
(3) All that can be done has been done.
(4) There is little that I can do for you.
注意：当先行词指人时，偶尔也可以用who
(4) Any man that/.who has a sense of duty won’t do such a thing.
2. 当先行词被序数词修饰
(1) The first place that they visited in London was the Big Ben.
3. 当先行词被形容词最高级修饰时
(1) This is the best film that I have seen.
4. 当形容词被the very， the only 修饰时
(1) This is the very good dictionary that I want to buy，
(2) After the fire in his house， the old car is the only thing that he owned.
当先行词指人时，偶尔也可以用who
(3) Wang Hua is the only person in our school who will attend the meeting/
5. 当先行词前面有who， which等疑问代词时
(1) Who is the man that is standing there？
(2) Which is the T-shirt that fits me most？
6. 当先行词既有人，也有动物或者物体时
(1) Can you remember the scientist and his theory that we have learned？
（二）关系代词as和which引导的定语从句
as和which引导非限制性定语从句，有相同之处也有不同之处。具体情况是：
1．As和which都可以在定语从句中做主语或者宾语，代表前面整个句子。
(1) He married her， as/which was natural.
(2) He was honest， as/which we can see.
2. as 引导非限制性定语从句，可放在主句之前，或者主句之后，甚至可以切割一个主句；which引导的非限制性定语从句只能放在主句之后。另外，as有“正如……，正像……”的意思
(1) As is known to all， China is a developing country.
(2) He is from the south， as we can see from his accent.
(3) John， as you know， is a famous writer.
(4) He has been to Paris more than several times， which I don’t believe.
注意：当主句和从句存在逻辑上的因果关系时，常用which
(5) Tom was always late for school， which made his teacher angry.
3. 当先行次受such， the same修饰时，常用as
(1) I have never heard such a story as he tells.
(2) He is not such a fool as he looks.
(3) This is the same book as I lost last week.
注意：当先行次由the same修饰时，偶尔也用that引导定语从句，但是和由as所引导的定语从句意思不同
(4) She wore the same dress that she wore at Mary’s wedding. 她穿着她在MARY婚礼上穿过的一条裙子。
(5) She wore the same dress as her young sister wore. 她穿着和她妹妹所穿的一样的裙子。
（三）以the way为先行词的定语从句通常由in which， that引导，而且通常可以省略。
(1) The way in which/ that/./ he answered the question was surprising.
(四) but有时也可以做关系词引导定语从句
(1) There are very few but understand his idea. ( but= who don’t )
(五) 区分定语从句和同位语从句
1．定语从句修饰先行词，它和先行词是修饰关系；同位语从句说明先行词的具体内容，是补充说明的关系
(1) The plane that has just taken off is for London. 定语从句
(2) The fact that he has been dead is clear. 同位语从句
2．定语从句由关系代词或者关系副词引导，关系词在句中充当成分，有时可以省略；同位语从句主要由that引导，在句中一般不做成分；句子也可以由when， where， how， why， whether， what等词引导，充当成分
(1) The news he told me is true.
(2) The news that he has just died is true.
(3) The problem that we are facing now is how we can collect so much money. 定语
(4) The problem how we can collect so much money is difficult to solve.
3. 同位语从句和先行词一般可以用be动词发展成一个完整的句子，而定语从句不可以
(1) The idea that we could ask the teacher for advice is wonderful. 同位语
(2) The idea was that we could ask the teacher for advice.
(3) The fact that the earth moves around the earth is known to all.
(4) The fact is that the earth moves around the earth.

一、考查关系代词that和 which的区别
1．Finally ，the thief handed everything _____ he had stolen to the police．（MET'87）
A．which B．what C．whatever D．that
2．All _____ is needed is a supply of oil．（MET'89）
A．the thing B．that C．what D．which
答案及简析：
1．D。2．B。that和which都能指物，在定语从句中作主语或宾语，但下列情况下，常用that，不用which：①先行词是all， everything，anything，nothing等不定代词。②先行词指物且被形容词最高级、序数词或all，no，only，the very，the last等修饰。③先行词既指人又指物。
二、考查关系代词whose
3．A child _____ parents are dead is called an orphan．（MET'86）
A．which B．his C．whose D．with
答案及简析：
3．C。关系代词whose在定语从句中作定语，修饰其后的名词，意为“……的”。有时“whose ＋n．”可转换为“n．＋of＋which ／whom”。如：
The building whose roof（＝the roof of which）we can see from here is a hotel．
This kind of book is for the students whose native language（＝the native language of whom）isn't English．
三、考查关系代词与关系副词的差异
4．After living in Paris for fifty years he returned to the small town _____ he grew up as a child．（NMET'96）
A．which B．where C．that D．when
5．I also enjoyed the evenings when we spent together．（NMET'95短文改错）
答案及简析：
4．B。5．去掉when或when→that／which。如何选用关系代词和关系副词呢？关键是看先行词在定语从句中作什么成分。决不能只按先行词是地点名词就用 where，先行词是时间名词就用when，先行词是reason就用why。有时，命题者还会在先行词与引导词之间加入附加成分，影响考生正常解题思路，做题时，要特别注意。
四、考查“介词＋关系代词”
6．He paid the boy ＄10 for washing ten windows， most of _____ hadn't been cleaned for at least a year．（MET'90）
A．these B．those C．that D．which
答案及简析：
6．D。“介词＋关系代词”引导的定语从句，关系代词一般只有which，whom。先行词是物时，用which，先行词是人时，用whom。介词的选定一般依据下列三点：①看定语从句中的形容词与哪一个介词组成固定搭配②看先行词与哪一个介词组成习惯搭配③看定语从句中的动词与哪一个介词组成习惯搭配。
五、考查非限制性定语从句与限制性定语从句的区别
7．Dorothy was always speaking highly of her role in the play，_____ ，of course，made the others unhappy．（NMET2000）
A．who B．which C．this D．what
8．I shall never forget those years _____ I lived in the country with the farmers，_____ has a great effect on my life．（上海94）
A．that；which B．when；which C．which；that D．when；who
答案及简析：7．B。8．B。原因见本期第2面。
六、考查as引导的非限制性定语从句
9．_____ is known to everybody，the moon travels round the earth once every month．（NMET2001）
A．It B．As C．That D．What
答案及简析：
9．B。as，which均可用来引导非限制性定语从句，代替整个主句，但as引出的从句可放在句首、句中或句末，which引出的从句通常只能放在主句后面。