伤心啊~~为了多找点资料，刚刚打上的都没了。
先用自己话给你总结吧，老师让我们记住，“代高序”原则，就是说先行词是不定代词，序数词，最高级，修饰时用that。为了让我们掌握老实说戴高乐的弟弟。就容易记住了。除此之外还用两种只能用that的情况，当先行词为the very
、the only、the time 等修饰时只能用that .还有就是当先行词既有人又有物是只能有that.
当先行词是人，缺主语时用who.
当先行词是物缺主语或宾语时用which.
累死我了啊~~下面是详细资料，我给你找的~
一 定语从句的构成：
A 下面是两个简单句：
I am reading a book.----------------The book was bought by my mum.
B 把两个简单句合在一起：
C 连接两个句子的成分有关系代词：that, which, who, whom, whose, 还有关系副词：
when, where, why.
更多例子：
1 The book (that) he borrowed from the library is very interesting.
2 The book that was written by Peter is a recent better-seller.
3 He embarked a ship that was heading for Shanghai.
4 He embarked a ship (that) the travel agency charted for $5000 a week.
B Which 连接两个单句，让它们成为复合句。
更多例子：
1 This is the book which has been translated recently by this guy.
2 This is the book (which) he has translated recently.
3 Yesterday, he went to the supermarket which has a very poor service.
4 He has finished translating the book (which) a famous author compiled
two years ago.
C Who 连接两个单句，让它们成为复合句。
总结：
更多例子：
1 The boy who is speaking to the girl is my brother.
2 The boy (who) I spoke to a minute ago is my brother.
3 Anybody who dares to break the law will be punished.
4 Our enemy will like the persons (who) we don’t like.
D Whom 连接两个单句，让它们成为复合句。
总结：
更多例子：
1 The man (whom) I saw yesterday is called Smith.
2 I have forgiven Jerry (whom) I blamed for breaking my glasses.
E Whose 连接两个单句，让它们成为复合句。
总结：
更多例子：
1 Dalian is a beautiful city whose football club is very famous.
2 John is a very famous singer whose family background is outstanding.
F When 连接两个单句，让它们成为复合句。
比较：
{ October 1st is the day.------------All Chinese will remember the day.(宾语)
October 1st is the day (that) all Chinese will remember.
{ October 1st is the day.-----The day has made thousands of Chinese excited.（主语）
October 1st is the day that has made thousands of Chinese excited.
{ October 1st is the day.----------PRC was founded on the day.(时间状语)
October 1st is the day when PRC was founded.
总结：
when 在引导定语从句时，通常情况下不可省略，但有时也有省略的情况出现。
更多例子：
1 September 11th is the day when many Americans were killed.
2 I will not forget last Tuesday when I received a very beautiful present
from my mum.
G Where 连接两个单句，让它们成为复合句。
比较：
{ { Jack is working in the factory.
His father visited the factory yesterday. (宾语)
Jack is working in the factory (that) his father visited yesterday.
{ { Jack is working in the factory.
The factory has produced thousands of cars.（主语）
Jack is working in the factory that has produced thousands of cars.
{ { Jack is working in the factory.
His father has worked for 25 years in the factory. (地点状语)
Jack is working in the factory where his father has worked for 25 years.
总结：
更多例子：
1 I am going to visit Beijing University where my brother is studying.
2 When I traveled to Beijing, I stayed in the Hilton Hotel where the service
was excellent.
H Why 连接两个单句，让它们成为复合句。
注意：
只有当先行词（被修饰的词）是the reason 时才能够用why 来引导定语从句。
更多例子:
1 That is one of the reasons (why) I asked you to come here.
2 He refused to tell the reason (why) he made this stupid mistake.
I 使用定语从句要注意的事项：
A 只用that 的三种情况:
1 当先行词是all, something, anything, everything, nothing, somebody,
anybody,everybody, nobody时:
1 That is all (that) I can give to you.
2 Please tell me something that is exciting.
3 I don’t like anybody that behaves rudely.
2 当先行词被形容词的最高级修饰时:
1 He is the cleverest student (that) I have ever taught.
2 This is the longest car that has ever existed.
3 当先行词是人和物时
1 On the river bank, I found a boy and dog that were walking together.
B 不用that 的两种情况:
1 在介词后面:
• 先行词是人，介词后面只用whom.
1 I don’t want to talk to the boy with whom I quarreled yesterday.
• 先行词是物，介词后面只用which.
1 Who is going to repair the broken chair on which I am sitting?
2 Please don’t touch the quilt in which the baby is sleeping.
2 在非限定性定语从句中 (如果从句和主句之间有逗号，那么这个从句是非限定性定语
从句)：
1 Many foreign students are studying in Beijing, which is the capital
of China.
2 I am talking to my cousin, who is a university student.
C 通常情况下，定语从句应尽量紧跟被修饰的先行词.
Wrong: The computer is not working well that he bought from this shop.
Right: The computer that he bought from this shop is not working well.
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