定语从句 定语从句是修饰名词或代词的从句。定语从句在句中起定语作用，被定语从句所修饰的词称为先行词。

引导定语从句的有： （1） 关系代词 that （2） 关系代词 who, whom, whose, which （3） 关系副词 when, where, why. what 不可以引导定语从句

指代对象 人 事物 人+事物 主格 who/that which/that that 宾格 who(m)/that 所有格 whose whose/of which

who, whom, that代表人 既可作动词的宾语，又可作介词的宾语，此时关系代词可以省略。 The girl whom/that you saw just now is Jane. = The girl you saw just now is Jane.

下列情况只能用who 而不能用that. 当先行词是 one, ones, anyone, those等 Anyone who does that must be mad. (2) 用在 there be 句型中 There is a young man who wants to see you. (3) 当先行词是人，后面有较长的修饰语时。 I met a friend of mine in the park yesterday who had got three gold medals in the Asian Games.

(4) 为了避免重复或引起歧义 The man that spoke at the meeting is our new headmaster who has just come from Shanghai. (5) 当先行词是I, you, he, they等时（常用于谚语）。 He who plays with fire gets burned. (6) 先行词如是指成员的集体名词， 关系代词也用who This class, who have the tickets will go to the theatre this morning.

(7) who 引导非限制性定语从句 He, who led the USA through these years, was shot on April 14, 1965. (8) 先行词如果是拟人化名词，关系代词也可用who. You will see the worker ants, who gather food for all the others. (9) 先行词指特定的人，多用who; 不指特定的人，多用that. The aunt who came to see us last week is my father’s sister. People that have not been properly trained can’t do this kind of work.

√ whose 指人或物，表所属关系。 Once there was a wise king whose name was Alfred. Have you seen a dictionary whose cover is blue? George Orwell, ____ was Eric Arthur, wrote many political novels and essays. the real name B. what his real name C. his real name D. whose real name √

The famous basketball star, ____tried to make a comeback, attracted a lot of attention. A. where B. when C. which D. who √ 2. He is the only one of the students who ____ a winner of scholarship for three years. A. is B. are C. have been D. has been √ 3. Have you seen the film Forrest Gump, ___ leading actor is world famous? A. its B. it’s C. whose D. which √

4. In the dark street, there wasn’t a single person ____ she could turn for help. A. that B. who C. from whom D. to whom √ 5. He was very rude to the customs officer, ____of course made things even worse. A. who B. whom C. what D. which √

限制性定语从句和非限制性定语从句 限制性定语从句对先行词起到限定区分的作用,并与先行词有着不可分割的关系,如果省去,剩下的部分意思不完整不清楚。 Those who want to go please put up your hands. A man who doesn’t try to learn from others can not hope to achieve much.

非限制性定语从句只对先行词作进一步的说明和解释，如果省去，剩余的部分仍然意义完整，表达清楚。 非限制性定语从句的前面往往有逗号与其余部分隔开。 Dr. Brown, who lives next door, comes from America. The snakes, which are poisonous, should be avoided.

专有名词具有“独一无二”的含义，因此通常用非限制性定语从句来修饰。 Hangzhou, which we visited last year, is one of the most beautiful cities in China. that 不能引导非限制性定语从句。其他引导限制性定语从句的关系代词、关系副词皆可引导非限制性定语从句，且不可省略。

在定语从句中作主语或宾语。在多数情况下，两者可换用。做宾语时，关系代词可省略。 that 和 which 指事物 在定语从句中作主语或宾语。在多数情况下，两者可换用。做宾语时，关系代词可省略。 Here is the dictionary which/that will be lent to you. The farm (which/that) we visited last Sunday was located in the suburbs of Beijing.

先行词具有下列情况之一者，引导定语从句的关系代词通常多用that, 不用或少用which. 先行词为everything, anything, nothing,all, much, little, few 等时。 Everything that can be done has been done. 但是， something 后的关系代词，用that, which 都可以

b. 当先行词被 the only, the very, the last 及序数词修饰时。 eg. This is the only food (that) I can find for you. This is the last thing (that) I will do.

c. 当先行词被形容词最高级修饰时。 eg. This is the most interesting film (that) I have ever seen. d. 当先行词既包括人又包括物时 eg. They talked for about half an hour of things and persons that they remembered in the school. e. 当关系代词在定语从句中做表语时 eg. China is not the country that it used to be.

f. 当先行词有 all, any, few, little, no等修饰语时，较多的使用 that. All the books (that) he has translated are very popular here. g. 被修饰词为数词时，只用that. He brought two cats yesterday. Now I can see the two that are playing in the garden.

h. 如果两个从句，其中一个关系代词引用which, 另一个用that 避免重复。 He built up a factory which produced things that had never been seen before. 主句是there be 结构，修饰其主语的定语从句用that. There is a book on the desk that belongs to Frank. j. 先行词为what, 关系代词用that. What that is on the table belongs to me.

有时为了避免重复而使用that 引导的定语从句。 Which is the car that hit the boy? Who was the man that she danced with?

通常使用which的场合 当关系代词后有插入语时 I have received your constructive letter which, as I have told you, was needed by the press. b. 在谚语中常用that which 的用法 That which is well done is twice done. c. 先行词是指物的that和those时，用which不用that. What’s that which he refused to accept?

The result of the experiment was very good, ___ we hadn’t expected. when B. that C. which D. what 2. Caral said the work would be done by October, ___ personally I doubt very much. it B. that C. when D. which All of the flowers now raised here have developed from those ___ in the forest. once they grow B. they grow once C. they once grow D. once grew √ √ √

as 引导的定语从句 （1） as 作关系代词和关系副词引导限制性定语从句，并在从句中做主语、定语或状语，构成 the same…as 和such…as 等结构。 I like the same book as you do.(as 做宾语) I shall do it in the same way as you did.(as 做状语) I want to have such a dictionary as you have.(as 做宾语)

当 the same修饰先行词时，引导定语从句的关系代词可用as, 也可用that。用that表示他所引导的内容与先行词所讲的事物是同一个；用as既可表示“同一”又可表示“同类”。 This is the same bicycle that I have lost. 这是我丢失的那辆自行车。 This is the same bicycle as I have lost. 这辆自行车跟我丢的那辆一样。

（2）as 引导非限制性定语从句。as 在定语从句中作主语、表语或宾语，这个定语从句说明整个句子，可以放在主句之前。 As we all know, he studies very hard. (as 代表整个句子，做宾语) As is known to all, he is the best student in our class.(as 代表整个句子做主语)

as is said above as already mentioned above as is known to all as it is as is often the case as is reported in the newspaper

when, where, why做关系副词引导定语从句 （1）when代替 at/in/on/during which, 在定语从句中作时间状语。 Tell me the time when (=at which) the train leaves. July, when(=in which) we can go home for a rest, is coming soon.

where 表地点，只能跟在表示地点的名词后，它在定语从句中做地点状语 This is the school where (=at which) I used to teach. What is the name of the town where (=in which) we stayed last night.

(3) why 指原因，引导从句修饰名词reason. why 可用that 替换，或省略。 I don’t know the reason (why/for which/that) he left here.

The reason why his sister was late is that her husband is dangerously ill in hospital. 句中why 不可用that 代替，以避免重复；that 不能用because 或why 替代。陈述句主语reason 的表语从句中只能用that 引导，that不做从句中的任何成份。 I didn’t know the reason (why) he was late. The reason why he was late was that his wife was ill. His wife was very ill. That’s why he was late. He was late. It was because his wife was very ill in bed.

关系代词做介词的宾语时 关系代词whom, which 在从句中做介词宾语时，可以和介词一起放在先行词和从句之间。为了使关系代词紧跟他所修饰的词，也可以把介词放在从句中有关动词的后面。 The athlete to whom you talked is a famous runner. b. 含有介词的短语动词一般不拆开，借此仍放在动词之后。 Is this the watch which he is looking for？

c. 关系代词that 在从句中做介词宾语时，介词不能放在它的前面，只能放在从句中有关动词的后面 The city that she lives in is very far away. d. 关系代词whose 也可以在从句中与它所修饰的名词一起做介宾短语 The boss in whose company my father worked is a very kind person.