定语从句中只用WHO - 360文档中心

初中英语重点语法——非限制性定语从句

初中英语重点语法——非限制性定语从句非限定性定语从句起补充说明作用，在句子中不充当成分，缺少也不会影响全句的理解，它与主句往往用逗号隔开。

定语从句有限制性和非限制性两种。

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，将非限定性定语从句放在句子中间，其前后都需要用逗号隔开。

1. who引导的非限制性定语从句Our guide，who was a French Canadian，was an excellent cook.我们的向导，一个法裔加拿大人，擅长于烹调。

My gardener，who is very pessimistic，says that there will be no apples this year.我家的园丁他非常悲观，他说今年将不结苹果。

2. whom引导的非限制性定语从句关系代词whom用于指人，在句中作动词宾语和介词宾语，作介词宾语时，介词可位于句末。

如：Peter, whom you met in London, is now back in Paris.彼得现在回巴黎了，你在伦敦见过他。

Mr Smith，from whom I have learned a lot，is a famous scientist.史密斯先生是一位著名的科学家，我从他那儿学了许多东西。

3. whose引导的非限制性定语从句whose是关系代词who的所有格形式，在从句中作定语。

whose通常指人，也可指动物或无生命的事物。

如：The boy, whose father is an engineer, studies very hard.那位小男孩学习很努力，他的父亲是位工程师。

Above the trees are the mountains whose magnificence the river faithfully reflects on the surface.在树林的高处是山，其壮丽的景色完全映照在河面上。

定语从句用who的八种情况

定语从句用who的八种情况
1、who引导主语从句：who作主语时所指的人做的动作，构成主语从句，例如：
Who visits the museum must pay for the ticket.
2、who 引导定语从句：who在定语从句中作定语，修饰先行词，如：
This is the man who I told you about.
3、who引导表语从句：who作表语，是谓语动词后面的成分，表此人的性格、状态，例如：
He is the man who can be trusted.
4、who 引导同位语从句：同位语从句起到补充说明的作用，who 的先行词是具体的人，如：
This is Tom, who is a kind person.
5、who 引导状语从句：who在状语从句中作目的状语，指代动作的发出者，如：
They came to visit us, who we haven't seen for a long time.
6、who 引导宾语从句：who所句修饰的先行词指人，既可以作宾语，如：
Mike asked who had done it.
7、who 引导宾补从句：who作宾补，在宾语从句中作宾补，既可以指人，又可以指物，如：
I asked him who helped us.
8、who 引导名词性从句：who既可以句做定语，也可以作名词性定语从句；很多时候和which的用法相近，如：
We all know the person who/which did a great job.。

定语从句易犯错误、that、who的固定用法

whom，who或that。
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1.Some of the girls I invited them did not come.
此句因删去them，因为从句的宾语时省略了whom/who.
2. Is this the photo which you took it last week?
应删去it，因为从句的宾语时关系代词which，无需再用it了。
二、把定语从句谓语动词的单、复数弄错。
误：Anyone who break the law will be punished．
正：Anyone who breaks the law will be punished．
译：任何违犯法律的人将被处罚。析：应改break为breaks，因为who指anyone，
3)This is the very book that belongs to him. He is just the person (that) we are looking for.
(RULE3)先行词被the only, the very, the same, the last, just the等修饰时。
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that和which在指物的情况下一般都可以互换, 但在下列情况下, 一般用that而不用 which。 2)This is the first book (that) he has read.
This is the best place (that) we have visited. (RULE2) 先行词被序数词或最高级修饰时。
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that和which在指物的情况下一般都可以互换, 但在下列情况下, 一般用that而不用 4) wWheicwhe。re deeply impressed by the teachers and the schools that we had visited there. (RULE4)当并列的两个先行词分别表示人或物, 用关系代词that

定语从句

一. 只用who 不用that的定语从句a. )先行词是指人的不定代词，如one, ones, anyone, no one, all, nobody, anybody, none, those等People all like those who have good manners.b. )There be 结构中，用who 指代人。

There were many people who were killed in the accidents.二．Nobody knows the reason why he is often late for school.The reason that/ which he gave was reasonable.He works in a factory _that/which_____makes TV sets.Is there a shop around __where_____I can have a cup of tea.三. 当先行词为point, situation, case, position, system, scene, sport, job, work, family，society, activity, stage, letter, context, accident, crime, condition ,platform, match, economy, environment等“模糊地点”的名词，且句子不缺成分时，用where引导定语从句。

We’re just trying to reach a point where both sides will sit down together and talk. 不缺We’re just trying to reach a point that was overlooked last time. 缺Football is a sport where players hold the ball and run with it. 不缺区别：This is where I disagree. (表语从句)………………. you are wrong.………………. Jim was murdered.………………..Tom lives.………………I put the book last time.四. “介词+关系代词which/whom”中介词和关系代词的选择1.)The train on which Tom travelled to Canada was very fast．2.)I’ll go to Beijing, in which case I’ll go to visit my aunt.3.)He broke his glasses, without which he could see nothing.4.)He made a hole in the wall, through which he could see everything in the room.5)He spent 4years in college, during which time// when he learnt a lot.6) Mr.li will move into the new house next Monday, by which time it will have been completely finished7）The professor can hardly find sufficient grounds on which to base his argument in favor of the new theory.注意：This is Mr.John for whose son I bought a book yesterday.He is the teacher with whose help I have made progress.Do you know the professor in whose hometown we stayed?The teacher in front of whose house stands a tall tree is very patient with his students五互换1.He has three sons, both of whom are doctors.3种=……………………, both of them (being) doctors.=……………………,and both of them are doctors2.Present at the meeting are many girls, half of whom are dressed in white. …………………………………………., half of them dressed in white. …………………………………………., and half of them are dressed in white.3.I read some books, the covers of which are yellow with years. whose covers4.There are 45 students in our class, most of whom are from the countryside.5.Our school attracts many students, of whom half come from India.（所属关系）6.The journey took us two years, of which three month was spent in the USA.7.The factory produced toys, 80% of which had been sold out.六as与which引导的非限制性定语从句的判定as引导的从句表示说话人对话语的看法、态度、解释或评论。

定语从句只用who

定语从句只用who定语从句只用who定语从句只用who篇一关系代词引导的定语从句1) who，which在句中.(2) as 代表前面的整个主句并在从句中作主语时，后一个必须重复前一个关系代词; that) you are carrying is about to come unwrapped.d)先行词既有人、宾语等, one 指人时One who doesn', smoking is harmful to one', smoking is harmful to one' that had never been seen before appears in the countryside。

关系代词和关系副词放在先行词和定语从句之间, nothing; that I saw yesterday, all。

定语从句分为限制性定语从句和非限制性定语从句, anyone，词组或代词即先行词, that 它们所代替的先行词是事物的名词或代词，则从句中的关系代词只能用which：Is he the man who/。

As we all know，例如：who.Finally, few、预料等时, where, which 引导非限定性定语从句的差别由as;that在从句中作主语）He is the man whom/。

1 , where they would be free to keep Negroes as slaves, as we expected.The sun heats the earth，不用which;m surprised the way how (by which) he works out the problem;结构, is very famous here.Beijing is the place where (in which) I was born, the name ofwhich I have forgotten;介词+ which"：a) 在引导非限定性定语从句时(错)The tree，"，而which不可。

定语从句只用who的情况

定语从句只用who的情况定语从句只用who的情况引导语：定语从句只用who的情况是？下面由店铺告诉你们吧，欢迎阅读！定语从句只用who的情况在定语从句中who和which都是关系代词，都在句中作主语，that除作主语以外还可以作宾语，指代人或物，而who只能指人。

1.只指人，并且在从句中作主语的情况A.The man who is a new one has rent a flat in downtown of New York for a long time.新来的这个人在纽约市中心租了一栋公寓，有一段时间了。

（the man 指人并在句中作主语）B.The girl who has looked for a job with the help of her tutor is fortunate.这个女孩在导师的帮助下找到了一份工作，她是幸运的。

（the girl 指人并在句中作主语）C.The professor who wrote a book is teaching history.写这本书的专家正在教历史。

（the professor既指人又在句中作主语）2.在非限定性定语从句中作主语，并指人时A.He feel honored to work with Mr.Li, who has good reputation in the business.他感到很荣幸和李先生一起工作，李先生在业界有着良好的声誉。

B.Where is the girl, who was the witness in the severe accident.作为这场严重车祸的目击者的`这个女孩在哪？C.The scientists, who invented a kind of immune medicine.科学家发明了一种免疫性的药物。

3.先行词是god, angel,fairy等词时，用who不用that。

英语定语从句的用法

英语定语从句的用法在英语中有很多种句式，今天让大家一起了解英语中定语从句的用法、接下来小编在这里给大家带来英语定语从句的用法，我们一起来看看吧!英语定语从句的用法定语从句由关系代词who、whom、whose、which、what、as 和关系副词where、when、why等引导，但须记住：1.what不能引导定语从句.2.关系词的分析须考虑它在定语从句中的成分。

一.指人的关系代词有who、whose、whom、that. 试分析：The old man who/whom /that we visited yesterday is a famous artist.Miss Wang is taking care of the child whose parents have gone to Beijing .The man with whom my father shook hands just now is our headmaster.(=The man who/whom that my father shook hands with just now is our headmaster.)注：A. 指人时有时只用who不宜用that。

1.先行词为one、ones或anyone(1)The comrade I want to learn from is the one who studies hard and works hard.(2)Anyone who breaks the law should be punished.2.先行词为these时These who are going to Beijing are the best students of our school.3.在there be 开头的句子中There is a student who wants to see you.4.一个句子中带有两个定语从句，其中一个定语从句的关系代词是that，另一个宜用who，以免重复。

英语的定语从句总结

英语的定语从句总结英语的定语从句总结所谓定语从句，就是在复合句中起定语作用以修饰主句中的名词或代词的从句。

下面是小编分享给大家的英语的定语从句总结，希望对大家有帮助。

英语的定语从句总结1一、关系代词引导的定语从句1、由who, whom, that，Whose引导的从句这些词代替的先行词是人的名词或代词，who作主语指人，whom作宾语指人，that既可作主语又可作宾语(作宾语可以省略)，可以指人也可以指物。

Whose 用来指人或物，只用作定语。

(1) Is he the man who/that wants to see you? 他是那个想见你的男人吗?(who/that在从句中作主语)(2) He is the man whom/ that I saw yesterday. 他就是我昨天见的那个人。

(whom/that在从句中作宾语)(3) The man whom you spoke to just now is our English teacher 你刚刚说话的那个男人是我们的英语老师(4) he man whose son is a doctor is our professor. 那个儿子是医生的男人是我们的教授。

2、由which, that引导的从句它们所代替的先行词是事物的名词或代词，在从句中可作主语、宾语等，作宾语时可以省略，例如：(1) Prosperity which / that had never been seen before appears in the countryside. 农村出现了前所未有的繁荣。

(which / that在从句中作主语)(2) The package (which / that) you are carrying is about to come unwrapped. 你拿那个包裹快要散开了。

(which / that在从句中作宾语)注意：代表物时多用which，但在下列情况中用that而不用which：a)先行词是anything, everything, nothing , none等不定代词时;b)先行词由every, any, all, some, no, little, few, much等修饰时，这时的that常被省略;c)先行词前有序数词或被形容词最高级修饰时;d)先行词中既有人又有物时;e)整个句中前面已有which，who,that时;f)当先行词为物并作表语时;g)先行词为one时;h)先行词同时又被the only,the very,the same修饰时;二、关系副词引导的定语从句1、when指时间在定语从句中做时间状语也可做连接词用I still remember the day when I first came to the school.2、where指地点在定语从句中做地点状语 Shanghai is the city where I was born.3、why指原因在定语从句中做原因状语，用在reason 后面。

定语从句who例句

定语从句who例句定语从句由关系词（关系代词、关系副词）引导，关系代词、关系副词位于定语从句句首。

以下是专门为你收集整理的定语从句who 例句，供参考阅读！定语从句who例句篇11.who指人在从句中做主语(1) The boys who are playing football are from Class One. 在踢足球的男孩们是一班的.(2) Yesterday I helped an old man who lost his way. 昨天，我帮助了一个迷路的老人.2. whom指人，在定语从句中充当宾语，常可省略。

（注：who 和whom已无太大区别，可以通用。

）(1) Mr. Liu is the person (whom) you talked with on the bus. 刘先生就是在公交车上和你聊天的那个人.(2) Mr. Ling is just the boy whom I want to see. 凌先生恰巧就是我想见的那个男孩.(3) The man who/whom you met just now is my friend. 你刚刚见到的那个人就是我的朋友.注意：关系代词whom在口语和非正式语体中常用who代替，可省略。

如果在从句中做宾语,就用whom或who.比如: He is the man whom/who I talk to. 他就是那个和我聊天的男人.如果是在从句中作主语就只能用who.比如: He is the man who has an English book. 他就是那个有英语书的男人.3.which指物，在定语从句中做主语或者宾语，做宾语时可省略(1) Football is a game which is liked by most boys. 足球是大多数男孩都喜欢的游戏.(2) This is the pen (which) he bought yesterday. 这是他昨天刚买的钢笔.4. that指人时，相当于who或者whom；指物时，相当于which。

定语从句只能用who

定语从句只能用who定语从句只能用who定语从句由关系词（关系代词、关系副词）引导，关系代词、关系副词位于定语从句句首。

在以下六种情况下多用who ：①关系代词在从句中做主语A friend who helps you in time of need is a real friend .②先行词为those ,people 时Those who were either fools or unfit for their offices could not see the cloth .③先行词为all,anyone ,ones ,one 指人时One who doesn’t work hard will never succeed in his work .④在There be句型中There is a stranger who wants to see you .⑤在被分隔的定语从句中A new teacher will come tomorrow who will teach you German .⑥在有两个定语从句的句子中,其一用who,其二用that,但若先行词后接两个以上的并列定语从句时,后一个必须重复前一个关系代词.The student who was praised at the meeting is the monitor that is very modest and studies very hard .There is a teacher who is always ready to help others and who enjoys what he does .这是我在高中的时候做的笔记,希望对你有用.定语从句中whose的用法一、whose为who的所有格，作“某(些)人的……”解，它所指代的先行词必须是人，其引导的定语从句修饰它的先行词，同时它本身在从句中作定语。

关系代词that和who的区别

关系代词that和who 的区别首先：用作关系代词的who 和that 都可以引导定语从句，用于指人，两者常可互换，但以下几点需注意：用法一：在all, nobody, no one, somebody, someone, anybody 等词之后两者都可用，但以用that 较普通。

例:Hands up, anyone who knows the answer.知道答案的请举手。

All who / that heard the story were amazed.听到这个故事的人都感到吃惊。

He was a man who was beloved by all who knew him.每一个他所认识的人都敬重他。

用法二：在序数词、形容词最高级以及the only, the same, the very 等之后两者都可用，但以用that 较普通。

例:She is the most beautiful girl I ever saw.她是我生平见过的最美丽的女孩。

用法三：引导非限制性定语从句时，通常只用who。

例: He confessed to his wife, who said she had thought as much. 他向妻子坦白了，他妻子说她事先已料到会如此。

Mrs Smith, who has a lot of teaching experience, will be j oining us next term.史密斯夫人很有教学经验，她下个学期将来与我们一道工作。

用法四：当先行词是一个既指人又指物的并列词组时，通常只用that。

例:He was watching the children and parcels that filled the car.他望着塞满车的孩子和包裹。

The passengers and the suitcases that were still waiting had to be transferred to another plane.仍在等待的乘客和行李只得改乘另一架飞机。

不定代词定语从句

不定代词定语从句⼤家了解不定代词定语从句⽤法吗？以下是店铺分享的不定代词定语从句⽤法，欢迎⼤家阅读参考！⼀、不定代词定语从句⽤法在限制性定语从句中,当先⾏词指⼈时,关系词可⽤who(作宾语是还可⽤whom)或that,⼆者常可互换. 但在下列情况中,⽤who(m),⽽不⽤that： (1) 当先⾏词是one,ones,any,few,anyone,anybody,someone,somebody,everyone, everybody等词时.如： Is there anyone who can answer this question? He was among the few who managed to live through the enemy prison camp. 注：在⾮正式⽂体中可以说：You’re the one that knows where to go.) (2) 当先⾏词是he,they,those,people,person等词时.如： He who wants to catch fish just not mind getting wet. Those who are against the proposal put up your hands. 注：在固定结构的谚语或习语中,可⽤he that….如： He that promises too much means nothing. (3) 当先⾏词有较长的后置定语修饰时.如： Do you know the writer in blue with thick glasses who is speaking at the meeting? (4) 在分隔式定语从句中,若先⾏词指⼈,为了明确修饰关系,应当⽤who(m).如： A new master will came tomorrow who will teach you German. There’s only one student in the school who/whom I wanted to see. I was the only person in my office who was invited. (5) 两个定语从句同时修饰⼀个指⼈的先⾏词,第⼆个定语从句常⽤who(m)来引导,如： She is the only girl I know who can play the guitar. ⼆、定语从句⽤法归纳定语从句由关系代词who、whom、whose、which、what、as和关系副词where、when、why等引导，但须记住： 1.what不能引导定语从句. 2.关系词的分析须考虑它在定语从句中的成分。

定语从句中关系词的使用

定语从句中关系词的使用▼关系词：关系代词：who, whom, that, which, whose关系副词：where, when, why▼关系代词的使用：一、who/ whom的用法二者都可指人，who在定语从句中作主语、宾语，whom在定语从句中作宾语→In this accident, the number of people who died reached as many as 25. 在这次事故中死亡人数多达25人。

→I have many friends to whom I am going to send postcards. 我要寄给很多朋友贺卡。

注意：①在限制性定语从句中作宾语的关系代词whom也可用who代替，非限制性定语从句中，whom不可用who代替；②但介词提前作宾语时不可以用who，只能用“介词+whom”。

例：→The person to whom you just talked is Mr Li.二、whose的用法Whose一般指人，有时也指物，在定语从句中作定语→You’re the only one whose advice he might listen to.只有你的建议他可能会听。

（whose在定语从句中作advice的定语）→I’d like a room whose window looks out over the sea.我想要一个窗户朝向大海的房间。

（whose在从句中作window的定语）三、which的用法Which一般指物，在定语从句中作主语、宾语，偶尔也作定语。

Which 在指人时往往指婴儿或指人的品质→The river which runs through the center of the city was polluted seriously.穿过市中心的那条河遭到了严重的污染。

（which在从句中作主语）→They stayed with me for three weeks during which time they drunk all thewine I had.他们和我一起待了三周，这期间他们喝光了我所有的酒。

英语定语从句的用法

英语定语从句的用法在英语中有很多种句式，今天让大家一起了解英语中定语从句的用法、接下来小编在这里给大家带来英语定语从句的用法，我们一起来看看吧!英语定语从句的用法定语从句由关系代词who、whom、whose、which、what、as 和关系副词where、when、why等引导，但须记住：1.what不能引导定语从句.2.关系词的分析须考虑它在定语从句中的成分。

一.指人的关系代词有who、whose、whom、that. 试分析：The old man who/whom /that we visited yesterday is a famous artist.Miss Wang is taking care of the child whose parents have gone to Beijing .The man with whom my father shook hands just now is our headmaster.(=The man who/whom that my father shook hands with just now is our headmaster.)注：A. 指人时有时只用who不宜用that。

1.先行词为one、ones或anyone(1)The comrade I want to learn from is the one who studies hard and works hard.(2)Anyone who breaks the law should be punished.2.先行词为these时These who are going to Beijing are the best students of our school.3.在there be 开头的句子中There is a student who wants to see you.4.一个句子中带有两个定语从句，其中一个定语从句的关系代词是that，另一个宜用who，以免重复。

英语语法顺口溜：定语从句5 - that who, who, Those people

英语语法顺口溜：定语从句5 - that who, who,Those people指人可用that who, 以下情况多用who;Those people做先行，There be的结构中；例句：1) Those who are for the plan, please raise your hands.赞成计划的人请举手。

2) People who create computer viruses are called hackers.制造电脑病毒的人被称为黑客。

3) There was once a little boy who came to the net bar to play games every night.以前有一个小男孩每天晚上都来网吧玩游戏。

先行指人不定代，从中做主who要在；先行词是指人的不定代词，如 one 、someone 、anyone 、nobody 等词，或指人的关系代词在定语从句中做主语，要用who, 而不用that。

例句：1）Nobody who knows a little scientific knowledge will believe you.懂得一点科学知识的人都不会相信你的话。

解析：nobody是指人的不定代词，用who, 不用that。

2）The thief who pretended to be a manager was caught stealing a car.那个装扮成经理的贼在偷车时被当场抓获。

解析：who指人，在定语从句中做主语。

两个定从一起来，不要重复你有才；一个先行词有两个定语从句时，关系代词要避免重复使用。

A plant that can cure diseases, which was known by the ancient Chinese , is called Chinese herbal medicine. 一种能够治病的，被古代中国人所熟知的植物，叫做中药。

英语定语从句中怎样用who

英语定语从句中怎样用who，whom，whose，that，which定语从句定语从句（Attributive Clauses）在句中做定语,修饰一个名词或代词,有时也可以修饰部分或整个句子.被修饰的名词,词组或代词即先行词.定语从句通常出现在先行词之后,由关系词（关系代词或关系副词）引出.关系代词有：who, whom, whose, that, which,as .关系副词有：when, where, why ,how .关系代词和关系副词放在先行词和定语从句之间,起连接作用,同时又可做定语从句的一个成分.当关系代词做宾语时可以省略.定语从句中的谓语动词必须在人称上和数量上和先行词保持一致.定语从句分为限制性定语从句和非限制性定语从句.1 、关系代词引导的定语从句1）who, whom, that这些词代替的先行词是人的名词或代词,在从句中所起作用如下：Is he the man who/that wants to see you?（who/that在从句中作主语）He is the man whom/ that I saw yesterday.（whom/that在从句中作宾语）2) Whose 用来指人或物,(只用作定语, 若指物,它还可以同of which互换),例如：They rushed over to help the man whose car had broken down. Please pass me the book whose (of which) cover is green.3)which, that它们所代替的先行词是事物的名词或代词,在从句中可作主语、宾语等,例如：A prosperity which / that had never been seen before appears in the countryside.（which / that在句中作宾语）The package (which / that) you are carrying is about to come unwrapped. (which / that在句中作宾语)关系代词that和which 都可以指物,that 和Who 都可以指人,其用法区别：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.c)多用who 的情况①关系代词在从句中做主语A friend who helps you in time of need is a real friend .②先行词为those , people 时Those who were either fools or unfit for their offices could not see the cloth . ③先行词为all, anyone , ones , one 指人时One who doesn’t work hard will never succeed in his work .④在There be句型中There is a stranger who wants to see you .⑤在被分隔的定语从句中A new teacher will come tomorrow who will teach you German .⑥在有两个定语从句的句子中,其一用who,其二用that,但若先行词后接两个以上的并列定语从句时,后一个必须重复前一个关系代词.The student who was praised at the meeting is the monitor that is very modest and studies very hard .There is a teacher who is always ready to help others and who enjoys what he does .2) 只能用that作为定语从句的关系代词的情况a) 在不定代词,如：anything, nothing, everything, all, much, few, any, little等作先行词时,只用that,不用which.All that is needed is a supply of oil.Finally, the thief handed everything that he had stolen to the police.b) 先行词有the only, the very, the just修饰时,只用that.He is the very man that helped the girl out of the water .c) 先行词为序数词(the last)、数词、形容词最高级时,只用that..The first English book that I read was “The Prince and the Pauper” b y Mark Twin .d) 先行词既有人,又有物时.He talked about the teachers and schools that he visited .e)当主句是以who 或which 开始的特殊疑问句时,用that 以避免重复.Who is the person that is standing at the gate .f)关系代词在从句中做表语He is not the man that he used to be .2 、关系副词引导的定语从句关系副词可代替的先行词是时间、地点、方式或理由的名词,在从句中作状语.1)when, where, why,how关系副词when, where, why,how的含义相当于"介词+ which"结构,因此常常和"介词+ which"结构交替使用,例如：There are occasions when (on which) one must yield.Beijing is the place where (in which) I was born.Is this the reason why (for which) he refused our offer?I’m surprised the way how (by which) he works out the problem .注意：①在非限制性定语从句中,"介词+ which"结构不能代替关系副词.如：They set up a state for their own , where they would be free to keep Negroes as slaves .②含有介词短语的动词一般不能拆开,介词仍放在动词后面.Is this the book which (that) she was looking for ?3、名词/数词/代词/形容词最高级+ 介词+ 关系代词引导定语从句She has written a book , the name of which I have forgotten .There are fifty-five students in our class , all of whom are working hard . There are five continents in the world , the largest of which is Asia .4、as, which 引导非限定性定语从句的差别：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.as可引导非限制性从句,常带有'正如'的意思.As is know, smoking is harmful to one's health.用法区别：(1) as 引导的定语从句可置于句首,而which不可.As we all know , he never smokes .(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..(3)非限定性定语从句中出现expect , think , suppose 等表示猜测、想象、预料等时.She succeeded in her doing the research work , as we expected .(4)As 的用法the same… as；such…as 中的as 是一种固定结构, 和……一样…….I should like to use the same tool as is used here .We should have such a dictionary as he is using。