形容词性从句（定语从句）
一个简单句跟在一名词或代词后进行修饰限定，就叫定语从句。
定语从句的从句作用是作定语，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，一般紧跟在它所修饰的先行词后面。
*定语与定语从句
Jack has a cute sister.
Jack has a sister who is very cute.
定语从句分为限制性定语从句和非限制性定语从句两种。限制性定语从句是先行词不可缺少的部分，去掉它主句意思往往不明确；非限制性定语从句是先行词的附加说明，去掉了也不会影响主句的意思，它与主句之间通常用逗号分开。如下面的非限定性定语从句：
Jack, who is 30 years old,has a cute sister.
定语从句的连词
限定性定语从句的连词
1、由连接代词who，whom，that，which，whose， as引导的限定性定语从句。
a, 先行词是人的名词或代词，引导词用who/whom/that, 如：
Is he the man who/that wants to see you?
He is the man who/whom/that I saw yesterday.
b, 先行词是事物的名词或代词，引导词用which/that, 如：
Is this the factory which/that makes TV sets?
The package which/that you are carrying is mine.
c, Whose作为引导词，只用作定语, 若指物，它还可以同of which互换, 如：
A child whose parents are dead is called an orphan.
Please pass me the book whose (of which) cover is green.
d, as引导的限定性定语从句, 如：
He is not such a fool as he looks.
I"ve bought the same dress as she is wearing.
2、由连接副词when，where，why引导的限定性定语从句。
a, 从句中缺时间状语，用when或介词＋which引导。如：
The day finally came when I was given a job.
The day finally came on which I was given a job.
b, 从句中缺地点状语，用where或介词＋which引导。如：
Please put the letter on the desk where he can easily find it.
Please put the letter on the desk on which he can easily find it.
c, 从句中缺原因状语或先行词是reason时，引导词用why/for which/that。如：
This is the reason why he didn"t come to the meeting.
This is the reason for which he didn"t come to the meeting.
This is the reason that he didn"t come to the meeting.
d, 当先行词是way时，其定语从句的引导词用that／in which。如：
The way that he looks at the problems is wrong.
The way in which he looks at the problems is wrong.
非限定性定语从句的连词
1、由连接代词who, whom, that, which, whose, as引导的非限定性定语从句。
a, 先行词是人的名词或代词，引导词用who/whom。如：
Joe, who is only five, has an inborn talent for music.
His wife, whom you met at my home, was a teacher.
Mr. Smith, from whom I have learned a lot, is a famous scientist.
b, 先行词是事物的名词或代词，引导词用which。如：
Her house, which was built a hundred years ago, stood still in the earthquake.
The Second World War, in which millions of people were killed, ended in 1945.
注意：无论先行词指人或指物，在句中作主语或作宾语，非限制性定语从句的引导词都不能用that。
c, 先行词在句中作定语，无论指人或者指物,引导词都用whose。如：
The girl, whose name is Kate, is the top of the students in our school.
The book, whose cover is red, is mine.
The story is about a girl, the name of whom is Jane.
The newly built café, the walls of which are painted light green, is a peaceful place for us.
d, as引导的非限定性定语从句, 代替整个主句。如：
The meeting was put off, as was exactly what we wanted.
Taiwan is, as you know, an inseparable part of China.
2、由连接副词when，where引导的非限定性定语从句。
a, 连接副词when在非限制性定语从句中作时间状语，指代主句中表示时间的词语。如：
He will put off the picnic until May 1st, when he will be free.
she didn"t sleep well in the first few days, when another girl shared the room with her.
Do you still remember the Sunday morning on which he left for America?
b, 连接副词where在非限制性定语从句中作地点状语，指代主句中表示地点的词语。如：
They went to London, where they lived for six months.
The next day we arrived in New York, where we were interviewed on the radio.
He studied in this high school, after which he went abroad.
注意：why不能引导非限定性定语从句。
定语从句的语序
定语从句的语序用陈述语序
Do you know the professor who is speaking at the meeting？
This is the house which we bought last month.
This letter is from his parents, who are working in Tibet.
The house, which we bought last month, is very nice.
定语从句的时态
定语从句中动词时态应根据句意及上下文而定，主从句可用不同的时态。
Where is the naughty boy whom I saw yesterday.
She was a good mother, who loved her children very much.
She is a good mother, who loves her children very much.
The trees near the house, which I planted three years ago, are growing up well.
定语从句的注意事项
先行词是物时，其引导词可用which也可用that，通常情况下二者可互换，如：
I bought an apple which/that is red.
但在有些情况下定语从句的引导词不能互换：
1. 用which不用that引导定语从句的三种情况；
a, 非限制性定语从句用which，不用that引导。如：
Football, which is a very interesting game, is played all over the world.
b, 先行词为that时，为了避免重复，定语从句用which不用that引导。如：
That which you borrowed from me wasn"t a real diamond necklace.
c, 介词后用which不用that引导。如：
The method with which you solved the problem is very good.
2. 用that不用which的七种情况；
a, 先行词前有形容词最高级或序数词修饰时，用 that不用which引导。如：
This is the best place that I have ever visited.
b, 先行词为little，much，all，none，few，（the）one， something，everything，nothing，anything等不定代词时，用that引导。如：
There is nothing in the world that can frighten him.
c, 先行词既有指人的名词又有指物的名词时，用 that引导。如：
He told us about the people and the cities that he had visited.
d, 先行词前有any，all，no，few，every，some，little， much，（the）very，（the）only，（the）last等词修饰时，用 that引导。如：
Is oxygen the only gas that helps fire burn.
e, 主句中含有which时，为了避免重复，用that引导。如：
Which is the book that you bought yesterday?
f, 先行词在主句中作表语且指人时，常用that引导。如：
He is no longer a little boy that he used to be.
g, 当主句是There be…句型时，用that引导。如：
There are two tickets for the film that are for you two.
one of类结构定语从句的主谓一致
a, 在“one of ＋复数名词＋定语从句”结构中，定语从句中谓语动词的单复数应由它修饰的先行词的数来决定。如：
He is one of the students that are never late.
This is one of the rooms that were damaged in the fire.
b, 在“the only one of ＋复数名词＋定语从句” 结构中，定语从句的谓语动词应用单数形式。如：
He is the only one of the students that is never late.
Mary is the only one of the youngest girls who plays in the band.
as与which引导定语从句的区别
as引导的定语从句可以放在句首、句中或句尾，which引导的定语从句可置于句中或句尾。
The tree, which is four hundred years old, is very famous here.
He is reading a book, which is about war.
As everyone knows, China is a beautiful country with a long history.
She did not, as her friend had feared, open the case.
I live a long way from work, as you know.
as引导的定语从句的常用句式：
The boy has made as much progress as we had expected.
I have never heard such a story as he tells.
This is the same book as I lost last week.
It is so big a stone as no one can lift.
As is known to all, he is the best student in our class.
As we all know, he studies very hard.
As is often the case, she is late.
As has been said above, grammar is not a set of dead rules.
定语从句练习题
选择正确的选项。
1. Alice received an invitation from her boss, ______ came as a surprise.
A. it
B. that
C. which
D. he
正确答案：C
2. Is this the museum ____ the exhibition was held?
A. where
B. that
C. on which
D. the one
正确答案：A
3. Don"t talk about such things of______you are not sure.
A.which
B.what
C.as
D.those
正确答案：A
4. There is only one thing _____ I can do.
A.what
B.that
C.all
D.which
正确答案：B
5. It there anyone in your class ______family is in the country?
A. who
B. who"s
C. which
D. whose
正确答案：D
