在复合句中修饰名词和代词的从句叫做定语从句.
被定语从句修饰的名词或代词叫做先行词.
引导定语从句的关系代词有who, whose, whom, which, that, as ;
引导定语从句的关系副词有when, where, why;
关系代词在定语从句中做主语,宾语,定语.
关系副词在定语从句中做状语.
一.由 who, 引导的定语从句,who在从句中做主语(口语中也可做宾语),
修饰表示人的先行词. 例如:
This is the man who helped me.
Do you know the comrade who spoke just now ?
The boy who//whom we saw yesterday is John’s brother.
二.whom引导的定语从句,whom在从句中作宾语,修饰表示人的先行词,
口语中可以省略.
The doctor (whom) you are looking for is in the room.
The person (whom) you just talked to is Mr. Li.
=The person to whom you just talked is Mr. Li. (介词后 whom不能省略)
The babies whom the nurses are looking for are very healthy.
(固定短语中的介词一般不省略,介词仍放在动词之后)
三.whose引导的定语从句,whose在从句中作定语,修饰表示人或物的先行词.
Do you know the woman whose name is Mary.
Pass me the dictionary whose cover is black.
四.that引导的定语从句,that在从句中做主语或宾语,修饰表示人或物的先行词,
作宾语时可省略,不能放在介词后面作宾语.
The letter (that//which) I received was from my father.
I can’t find the letter that//which came this morning.
Do you still remember the days (that//which)we spent together ?
This is the man that//who helped me.
The house (that//which) we live in is not large.
=The house in which we live is not large.
The doctor (that//whom //who)you are looking for is in the room.
五. which引导的定语从句,which在从句中做主语,也可做宾语,或介词的宾语,
修饰表示物的先行词. 先行词可以是词、短语、句子.
This is the book (which/that ) you want.
The building which//that stands near the river is our school.
The room in which there is a machine is a workshop.(介词后面的which不能省略)
The house (which/that) we live in is not large.
This is the watch (which/that ) he was looking for.
(在含有介词的动词固定词组中,介词只能放在动词之后,不能放在which之前 )
六、that 和which 都可以修饰表示物的先行词, 但是下列情况只能用that.
①. 先行词为不定冠词all, few, little, much, everything, nothing 等.
All (that) you have to do is to practise every day.
There isn’t much (that) I can do.
②. 先行词被序数词或形容词的最高级所修饰时.
The first lesson (that) I learned will never be forgotten.
This is the best film (that ) I have ever seen.
③. 先行词被all, any, every, few, little, no, some 等不定代词修饰时.
I have read all the books (that) you gave me.
④. 先行词被the only, the very, the last, the same 等修饰时.
The white flower is the only one that I really like.
This is the very book that I want to read.
This is the same book that I want to read. (同一本书)
----This is the same book as I want to read.
⑤. 当主句以who或 which 开头的特殊疑问句时,定语从句that 引导.
Who is the man that is standing there ?
Which of us that knows something about physics doesn’t know this ?
⑥先行词既有人又有物时.
We talked about the persons and things that we could remember.
⑦time做先行词,前面如果有序数词或 last 来修饰时,定语从句用 that 来引导或省略；如果没有序数词或 last 来修饰时,既可用 when 也可用that来引导.
This is the last time ( that ) I shall give you a lesson.
The first time ( that ) I saw him was in 1972.
It’s time ( that ) we got up.
七、as 引导的定语从句,
as用作关系代词和关系副词引导限定性定语从句,在从句中作主语、定语、表语、或状语,常与the same … as; such… as , so… as , as… as 连用.
I like the same book as you do.
I want to have such a dictionary as he has.
I shall do it in the same way as you did.
He is the same age as you ( are ).
He will give you such information as will help you.
Such students as you have mentioned should be criticized.
=Students such as you have mentioned should be criticized.
在the same…后也可用that引导定语从句,但意义有所不同：
that 引出的定语从句,指的是与先行词同一事物；而 as引出的定语从句是与先行词相似的'同类事物.
I want to use the same tool that I used yesterday.
I want to use the same tool as I used yesterday.
八、由when 引导的定语从句,修饰表示时间的先行词,when为关系副词,
做定语从句的时间状语.
I still remember the day when I first came to Beijing.
I still remember the day on which I first came to Beijing.
( 介词＋which可以代替 when)
I’ll never forget the time when we worked on the farm.
[I remember the days which//that we spent together.]
九、由where 引导的定语从句,修饰表示地点的先行词,where为关系副词,
做定语从句的地点状语.
This is the place where we lived for five years.
The factory where his father works is in the west of the city.
The factory in which his father works is in the west of the city.
( 介词＋which可以代替where)
[ This is a place which//that I wanted to visit. ]
十、Why引导的定语从句,why做原因状语.
I know the reason why he came late.
The reason why he was late was that he was ill.
非限定性定语从句
1. who 指人,做主语.
Yesterday I met Li Ping, who seemed to be very busy.
2. whom 指人, 作宾语.
He had many friends, many of whom had been in the universities.
3. whose 指人, 作定语.
The Chairman’s daughter, whose name is Ann, gave Tom a smile.
4. which 指物, 做主语,宾语.
His speech, which bored everyone, went on and on.
The speech, which he had written on the paper, seemed endless.
5. where 指地点, 作状语.
Galileo lived in the city of Pisa, where there is a leaning tower about 180 feet high.
6. when 指时间,作状语.
The meeting will be put off till next month, when we will have made all the preparations.
7. as 做主语,表语,宾语; 先行词可以是一个词,一个短语或一个句子.
To shut your eyes to facts, as many of you do, is foolish.
As we all know, he studies very hard.
As 引导的定语从句可放在主句前,也可放在主句后.在很多情况下已经
构成固定搭配.
As everybody can see as was usual
As can be seen as I expected
As is known to all, as may be imagined
as you know as is expected
as has been said before as is reported
as is often said as is announced
限定性定语从句和非限定性定语从句的区别：
限定性定语从句是先行词在意义上不可缺少的定语,如果去掉,主句的意思就不完整或失去意义.这种从句和主句的关系十分密切,写时不用逗号分开.
非限定性定语从句和主句的关系不十分密切,只是对先行词作些附加的说明,如果去掉,主句的意思依然清楚.这种从句和主句之间往往用逗号分开,一般不用that 引导.
as和 which 引导的非限定性定语从句的比较：
1. 非限定性定语从句位于句未,而且as 和which 在从句中作主语、宾语、表语时可互换.
He is a farmer, as/which is clear from his manner.
This elephant is like a snake, as/which anybody can see.
2.which 引导的非限定性定语从句一般放在句未,而as 引导的非限定性定语从句可放在句未,也可放在句中、句首. 放在句首时不能用which 替换.
Crusoe lost his dog, which made him very sad
Taiwan is part of China, as/which is known to all.
As we have seen, oceans cover more than 70 percent of the earth.
3.as引导非限定性定语从句时,意为“这一点、这件事”,常与 see, hope,expect,know,guess等动词搭配；而which引导非限定性定语从句时与主句有一种因果关系,可译为“所以……”.
Cyprus, as you all know, is in the Mediterranean.
Bamboo is hollow, which makes it very light.
4. as引导非限定性定语从句并在从句中作主语时,其后面的谓语动词大多数必须是连系动词.如果从句谓语动词是行为动词,则必须用which.
He married her, as was natural.
She refused to take the medicine, which made her mother angry.
学习定语从句免不了要进行句法结构和语法成分的分析，而这往往是学生的薄弱环节，故此，在学习定语从句之前，学生应打好两方面的基础。以下是关于句子合并定语从句，欢迎阅览!
句子合并定语从句：
1.He has two sons .They both joined the army three years ago
2.He visited the Summer Palace this summer.He went there four years ago
3.He lied to his mother.It made her very angry
4.I have many books.Some of the books are about English
5.He met Liu Xiang in the street the other day.It made overjoyed
定语从句解题方法
一、选准关系代词和关系副词
在定语从句中，关系代词或关系副词都代替先行词在从句中充当一定的成分，如果该从句中缺少主语、表语、宾语或定语，就要用关系代词来连接从句;如果从句中缺少状语，就得用关系副词来连接从句。例如：
(1) I still remember the days which / that we spent together.
(2) I still remember the days when we worked together.
二、了解仅用that 引导限制性定语从句的几种情况
that 在限制性定语从句中既可指人又可指事或物。在下列情况下，只能用that 来引导定语从句：
1. 先行词是all , much, few, little, everything, anything, nothing 等不定代词时。例如：
Is there anything that you want to buy?
2. 先行词被all, few, little, much, every, some, no等词修饰或被the only, the very, the same, the last 等限定词修饰时。例如：
These are all the pictures that I have seen.
This is the very dictionary that is of great help.
3. 先行词既指人又指物时。例如：
My father and his teacher talked a lot about the things and the persons that they could remember.
4. 关系代词在定语从句中作表语时。例如：
Our school is not the one that it used to be.
5. 先行词被形容词最高级或序数词修饰时。例如：
This is the best English film that I have ever seen.
The first English novel that I read was A Tale of Two Cities.
6. 主句是who 或which 引导的特殊问句时。例如：
Who is the girl that is standing under the tree?
Which is the machine that we used last Sunday?
三、把握“介词+关系代词”结构中介词的选用
介词的选择与主句中先行词的搭配密切相关。例如：
That's the reason for which he was late for school.
This is the book on which I spent 8 yuan.
注意：
1. 定语从句中谓语动词是含有介词的动词短语时，介词应放在动词之后，不能拆开放在关系代词前。例如：
This is the key which you are looking for.
This is the baby whom you will look after.
2. 该结构中，关系代词指人时用whom，指物时用which.
四、弄清as 和which 引导的非限制性定语从句指代整体时的区别
1位置上的区别：
as 引导的非限制性定语从句的位置比较灵活，可以放在主句前，也可以放在主句后，还可插在主句的中间;而which 引导的非限制性定语从句只能放在主句之后。例如：
As is known to us all, the earth turns around the sun.
The earth, as is known to us all, turns around the sun.
The earth turns around the sun, as is known to us all.
The earth turns around the sun, which our parents once told us when we were very young.
2词义与联系上的区别：
as 引导的非限制性定语从句与主句之间有着较为密切的上下文联系，as 本身含有“正如”之意;而which 引导的非限制性定语从句与主句之间在逻辑意义上近似并列句，which 本身表示“这”或“这一点”之意。例如：
Light travels faster than sound, as we all know.
Jack came late for school, which made his teacher angry.
五、注意定语从句的主谓一致性
关系代词在定语从句中作主语时，从句的谓语必须与先行词保持人称和数的一致。例如：
Tom is one of the boys who are from the USA.
Tom is the only one of the boys who is from the USA.
六、保持主句的.完整性并避免从句成分的重叠
1. 在定语从句中，不管出现任何情况，主句的结构必须完整，即主句必须有主语和谓语，缺一不可，否则，整个主从复合句就无法成立。试比较：
(1)Is this factory _______ we visited last week?
(2)Is this the factory _______ we visited last week?
A. which B. where C. what D. the one
分析：
第一题缺少表语，只有填D项才能保持主句的完整性，而其他的选项均为干扰项。
第二题主句本身完整，应填的关系代词在从句中作visited 的宾语，故应选A项。
2. 从定语从句中，关系代词或关系副词已经代替先行词独立地或与相应的介词一起在定语从句中充当了一定的成分，因此在定语从句中就不能再出现与关系代(副)词重叠的成分。例如：
错句：Is this the train that they took it last Sunday?
分析：该题中that 已经代替先行词the train 在定语从句中充当及物动词took 的宾语，故重叠出现的宾语it必须删去。
总之，突破了以上六道难关，定语从句中的难题便会迎刃而解。
定语从句的'英文句子
1.this is the book which i like the most.
2.the box which is full of books should be empty as soon as possible.
3. i am the one who wrote to you.
4.the teacher who teaches us maths is a young man.
5.i want to find a place where is quiet and good.
6. the restaurant where we had our lunch last time is in tha 17th street.
7.the book that you borrowed from me yesterday is helen's ,not mine.
8.the dog that is eating over there belongs to the shopkeeper.
9.i like the movie that i watched yesterday.
10.do you think the picture that is taken by john is good?
