高中限制性定语从句及非限制性定语从句概念区别及练习-含答案
英语中限制性定语从句和非限制性定语从句讲解和练习
定语从句讲解和练习一、概念: He is the boy who often goes to school late.先行词关系词定语从句They have a clever son.Do you know the man over there?I know the man who wrote the book.二、原则： a.定语从句必须紧紧地跟在先行词后面，限制修饰先行词。
b.定语从句必须用关系词来引导。
c.关系词在定语从句中作一个句子成分.三、扩大. She is the old woman whom I saw this morning.Mary is the girl whose parents work in Japan.Is this the key which you are looking for?October 1, 1949 is the day when New China was founded.This is the house where the great man was born.I don’t know the reason why she looks unhappy today.四、下列定语从句只能用that来引导：1.先行词为形容词最高级所修饰This is the longest bridge that I have ever seen.2.先行词为序数词所修饰This is the first composition that he has ever written in English.3.先行词既包括人又包括物They talked of things and persons that happened in the school.He talked about the teachers and schools that he had visited.4.主句是who或which开头的特殊疑问句中的定语从句Who is the man that came this morning?Which is the bag that you lost?5.先行词为the only, the very, the last, the same所修饰的定语从句He is the very person that the police are looking for.This is the only thing that I can remember.6.先行词是everything, nothing, something, all, little, much,everybody等不定代词Tell us everything that you know, please.Is there anything that you don’t understand?7.先行词被all, every, no, some, any, little, much修饰时All that glitters is not gold.I’ve read all the books that you gave me.五、只用which 情况有两种情况：1、非限制性定语从句，关连词要用which；2、做介词宾语时只能用which。
限制性定语从句以及非限制性定语从句的区分、用法
限制性定语从句以及非限制性定语从句的区分、用法限制性定语从句以及非限制性定语从句的区分、用法根据定语从句与先行词的关系，定语从句可分为限制性定语从句及非限制性定语从句。
限制性定语从句紧跟先行词，主句与从句不用逗号分开，从句不可省去；非限制性定语从句主句与从句之间有逗号分开，起补充说明作用，如省去，意思仍完整。
以下是店铺整理的限制性定语从句以及非限制性定语从句的区分、用法，一起来看看吧。
一、限制性定语从句1.关系代词that既可代表事物也可代表人，which只代表事物，它们在从句中作主语或宾语。
在从句中作宾语时常可省略。
I was the only person in our office that was invited to the palace ball．The present that（which）I received last week was from my sister．This is a book which is about space rocket technology．2.关系代词who和whom引导的从句用来修饰人，分别作从句中的主语和宾语，whom作宾语时，要注意它可以作动词的宾语也可以作介词的宾语。
如：This is the man who helped me．The doctor whom you are looking for is in the room．3. whose是关系代词，修饰名词，作定语，相当于who和whom 的所有格，既可以修饰人又可以修饰物。
如：Do you know the student whose name is Wang Fei？We lived in a room whose window opens to the west.4. where是关系副词，用来引导表示地点的定语从句，where在从句中作状语。
如：At last we arrived at a small village where we’ll work for a week.5. when是关系副词，引导定语从句表示时间，在从句中作状语。
高中语法难点-限制性定语从句和非限制性定语从句的判断
限制性定语从句和非限制性定语从句的判断一．限制性定语从句在意义上有“涉他性”，而非限制性定语从句在意义上有“唯一性”试比较:I have a brother who works in a chemical works.我有一个在化工厂工作的哥哥。
(言外之言：我还有别的哥哥，他或他们不在化工厂工作)I have a brother, who works in a chemical works.我有一个哥哥,他在化工厂工作。
(暗示再没有别的哥哥了)All the books there which have pictures in them, were written by them.那儿所有有插图的书都是他们写的。
(言外之言:那儿还有没有插图的书,而那些书不是他们写的)All the books there, which have pictures in them were written by them.那儿所有的书都是他们写的，书中有插图。
(暗示那儿没有别的书了)二．当先行词为专有名词时其从句通常是非限制性的因为专有名词是某人、地方、机构等特有的名称，无需再加限定例如:Abraham Lincoln, who led the United States through these years, was murdered on April 14, 1865 at a theatre in Washington.亚伯拉罕·林肯领导美国度过了这几个年头，可他却于1865年4月14日在华盛顿的一家戏院被暗杀了。
One of the most colourful figures in boxing history was Daniel Mendoza who was born in 1764. 但尼尔孟多亚是拳击史上最引人注目的人物之一,他生于1764年。
如果专有名词前有定冠词,其后的定语从句可能是限制性的，因为这时有可能特指两个或两个以上同名的专有名词中的一个。
限制性非限制性定语从句详解+练习附答案
定语从句用来说明主句中某一名词或代词（有时也可说明整个主句或主句中一部分）而起定语作用的句子叫作定语从句。
一．词引导的定语从句1. 关系代词用来指代先行词是人或物的名词或代词句子成分用于限制从句或非限制性从句只用于限制性从句代替人代替物代替人或物主语 Who which that主语 Whom which that宾语 Whose(=of whom) whose(=of which)例1：This is the detective who came from London.例2：The book which I am reading is written by Tomas Hardy.例3：The desk whose leg is broken is very old.例4：This is the room that Shakespeare was born in.2．关系代词的用法(1) 如果先行词是all, much, anything, something, nothing, everything, little,none等不定代词，关系代词一般只用that，不用which。
例如：All the people that are present burst into tears.(2) 如果先等词被形容词最高级以及first, last, any, only, few, much, no, some,very等词修饰，关系代词常用that,不用which, who，或whom。
例如：(3) 非限制性定语从句中，不能用关系代词that,作宾语用的关系代词也不能省略。
例如：There are about seven million people taking part in the election, most of whom、are well educated.(4) which还有一种特殊用法，它可以引导从句修饰前面的整个主句，代替主句所表示的整体概念或部分概念。
限制性定语从句和非限制性定语从句练习题
The person who I met yesterday was friendly. (正确答案：The person, who I met yesterday, was friendly.)
改错题2
The book that I borrowed from the library is very useful. (正确答案： The book, which I borrowed from the library, is very useful.)
这句话中的定语从句是“that you lent me”，修饰先行词 “the book”，表示“你借给 我的那本书”。这是一个限制 性定语从句，因为它对“the book”进行了限定，说明是哪 一本书。
She has a brother, who is a doctor.
这句话中的定语从句是“who is a doctor”，修饰先行词“a brother”，表示“她的一个兄 弟”。这是一个非限制性定语 从句，因为它对“a brother” 进行了补充说明，而不是限定。
“to me”。
改错题2
She has a brother, and he is a doctor.
04 答案及解析
答案
限制性定语从句答案：C 非限制性定语从句答案：B
解析
限制性定语从句解析
题目中的限制性定语从句是“that you borrowed”，它用来修饰名词“book”，指明是哪一本书。在限制性 定语从句中，关系代词“that”充当宾语，指代被修饰的名词，不可省略。因此，正确答案是C。
改错题4
The place where I went on holiday was very relaxing. (正确答案：The place, where I went on holiday, was very relaxing.)
限制性定语从句与非限制性定语从句的区别
她收到了老板的邀请，这是她意想不到的。
误：She received an invitation from her boss, that came as a surprise.
正：She received an invitation from her boss, which came as a surprise.
4. 含义不同
比较： She is my sister who is a doctor. 她是我那个当医生的姐姐。 (暗含姐姐不止一个) She is my sister ,who is a doctor. 她是我姐姐，她是当医生的。 (没表示有几个姐姐)
5. 先行词不同
限定性定语从句的先行词只能是名词 或代词，而非限定性定语从句的先行词则 可以是名词或代词，也可以是短语或句子； 另外，当先行词为专有名词或其他具有独 一无二性的普通名词时，通常要用非限定 性定语从句，而不用限制性定语从句：
study abroad. 她父亲很有钱，希望她出国学习。
(先行词为表独一无二意义的普通名词，要用非限
制性定语从句修饰)
6. 关系词不同
关系词that和why可用于限制性定语从 句中，通常不用于非限制性定语从句；另 外，在限制性定语从句中，关系词有时可 以省略，而在非限定性定语从句中关系词 一律不省略。
3. 翻译不同
在翻译定语从句时，一般把限定性定 语从句翻译在它所修饰的先行词之前，而 把非限定性定语从句与主句分开： He is the man whose car was stolen. 他就是汽车被窃的那个人。 I’ve invited Jim, who lives Байду номын сангаасn the next flat. 我邀请了吉姆，他就住在隔壁。
最新限制性非限制性定语从句详解+练习(附答案)
定语从句用来说明主句中某一名词或代词（有时也可说明整个主句或主句中一部分）而起定语作用的句子叫作定语从句。
一．词引导的定语从句1. 关系代词用来指代先行词是人或物的名词或代词句子成分用于限制从句或非限制性从句只用于限制性从句代替人代替物代替人或物主语 Who which that主语 Whom which that宾语 Whose(=of whom) whose(=of which)例1：This is the detective who came from London.例2：The book which I am reading is written by Tomas Hardy.例3：The desk whose leg is broken is very old.例4：This is the room that Shakespeare was born in.2．关系代词的用法(1) 如果先行词是all, much, anything, something, nothing, everything,little, none等不定代词，关系代词一般只用that，不用which。
例如： All the people that are present burst into tears.(2) 如果先等词被形容词最高级以及first, last, any, only, few, much, no, some, very等词修饰，关系代词常用that,不用which, who，或whom。
例如：(3) 非限制性定语从句中，不能用关系代词that,作宾语用的关系代词也不能省略。
例如：There are about seven million people taking part in the election, mostof whom、are well educated.(4) which还有一种特殊用法，它可以引导从句修饰前面的整个主句，代替主句所表示的整体概念或部分概念。
高中英语限制性定语从句和非限制性定语从句有四大区别及练习华师大版
限制性定语从句和非限制性定语从句有四大区别;一、在句中作用不同限制性定语从句对被修饰的先行词有限定制约作用;使该词的含义更具体;更明确..限制性定语从句不能被省略;否则句意就不完整..非限制性定语从句与先行词关系不十分密切;只是对其作一些附加说明;不起限定制约作用..如果将非限制性定语从句省去;主句的意义仍然完整..二、外在表现形式不同限制性定语从句因与先行词关系密切;所以不可以用逗号将其与主句隔开；而非限制性定语从句与先行词关系不十分密切;所以可用逗号将其与主句隔开..例1. This is the place where he used to live.例 2. Mr. Zhang;who came to see me yesterday;is an old friend of mine.在例 1中;定语从句与先行词关系密切;为限制性定语从句;不可用逗号将其与主句隔开..在例2中;定语从句与先行词关系不密切;为非限制性定语从句;可用逗号将其与主句隔开..三、先行词内容有所不同大多数限制性和非限制性定语从句的先行词往往为某一个词或短语;而特殊情况下非限制性定语从句的先行词也可为整个主句;此时非限制性定语从句常由 which 引导..例：1. A middle-aged woman killed her husband;which frightened me very much.由语境可知;令“我”恐惧的内容应为“中年女子杀害了自己的丈夫”这整个一件事;因此先行词为整个主句;此时应由 which 引导定语从句..例：2. A five-year-old boy canspeak two foreign languages; which surprises all the people present.由语境可知;令所有在场的人感到惊讶的内容是“一个五岁男孩会讲两门外语”这整个一件事;因此先行词为整个主句;此时应由 which 引导非限制性定语从句..四、关系词的使用情况有所不同一 that 不可用于引导非限制性定语从句所有关系代词和关系副词均可引导限制性定语从句;大多数关系代词和关系副词可引导非限制性定语从句;但 that 不可..例如：他没通过这次考试;令我很失望..误：He didn't pass the exam;that disappointed me.正：He didn't pass the exam;which disappointed me.值得注意的是;不少同学误认为只有 which 才能引导非限制性定语从句;这个观点是不正确的..使用非限制性定语从句时;如果先行词指人;则用 who ; whom或 whose 引导非限制性定语从句；先行词指物可用 which 引导非限制性定语从句；先行词表时间或地点且在从句中作时间状语或地点状语时;可用when;where 引导非限制性定语从句..例1. We'll graduate in July;when we will be free.例2. Last Sunday they reached Nanjing;where a conference was to be held.二关系代词替代情况不同关系代词 whom 在限制性定语从句中作宾语时可用 who 代替 whom ;但 whom 在非限制性定语从句中作宾语时不可用 who 来代替..例: 1. This is the girl whom I met in the street.先行词 the girl 在限制性定语从句中作宾语;可用 who 代替whom .例: 2. A young man had a new girl friend;whom he wanted to impress.先行词 a new girl friend 在非限制性定语从句中作宾语;不可用 who 代替 whom .在限制性定语从句中;先行词指人时可用 that 代替 who/ whom ;但在非限制性定语从句中先行词指人时;不可用 that 代替who/whom .例：她有一个姐姐;她是教师..误： She has a sister;that is a teacher.正：She has a sister;who is teacher.三关系代词省略情况不同关系代词在限制性定语从句中作宾语时可以省去;非限制性定语从句的所有关系词均不可省..例 1. This is the bookwhich/thathe lost yesterday.先行词 the book 在限制性定语从句中作宾语;关系代词 which 或 that 可以省略..例 2. The book; which he lost yesterday; has been found.先行词 the book 在非限制性定语从句中作宾语;关系代词which 不可省..四as引导定语从句时的用法① as引导限制性定语从句通常用于the same … as; such … as 结构中..e.g. I want the same shirt as my friend’s.Such machines as are used in our workshop are made in China. 我们车间使用的这种机器是中国制造的..② as引导非限制性定语从句既可放在主句之前;也可放在主句之后;用来修饰整个句子..通常用下列句型：as is known to all; as is said; as is reported; as is announced; as we all know; as I expect 等..e.g. As I expected; he got the first place again in this mid-term examination.3as 引导非限制性定语从句时与which的区别① 当主句和从句语义一致时;用as；反之;用which来引导非限制性定语从句..e.g. He made a long speech; as we expected.He made a long speech; which was unexpected.② 当非限制定语从句为否定时;常用which引导..e.g. Tom drinks a lot every day; which his wife doesn’t likeat all.2. 定语从句有时不直接紧靠先行词;中间由一个定语、状语或谓语隔开..这种定语从句叫做分隔性定语从句e.g. There is an expression in his eyes that I can’t understand.4. 引导定语从句的关系副词有时可以用“介词+ which”来代替..e.g. October 1; 1949 was the day on which = when the People’s Republic of China was founded.5. 当定语从句中谓语动词是带介词或副词的固定短语动词时;短语动词的各个固定部分不要拆开..e.g. The sick man whom she is looking after is her father.6. 介词在关系代词前;只能用which和whom;且不能省略；介词在句尾;关系代词可以省略..定语从句练习、一、把下列每对句子合并成含有定语从句的主从复合句：1. The fan is on the desk. You want it.2. The man is in the next room. He brought our textbooks here yesterday.3. The magazine is mine. He has taken it away.4. The students will not pass the exam. They don’t study hard.5. The woman is our geography teacher. You saw her in the park.6. The letter is from my sister. I received it yesterday.7. The play was wonderful. We saw it last night.8. The train was late. It was going to Nanning.9. The boy is my brother. He was here a minute ago.10. The tree is quite tall. He is climbing it.11. Here is the girl. Her brother works in this shop.12. That’s the chi ld. We were looking at his drawing just now.13. This is the boy. His sister is a famous singer.14. I want to talk to the boys. Their homework haven’t been handed in.15. Is that the woman Her daughter is in my class.16. He used to live in a big house. In front of it grew many banana trees.17. They passed a factory. At the back of the factory there were rice fields.18. The soldier ran to the building. On the top of it flewa flag.19. In the evening they arrived at a hill. At the foot of the hill there was a temple.20. She came into a big room. In the middle of it stood a large table.二、根据句子意思;用介词＋关系代词whom或which 完成下列句子.1. The person ________ ________ I spoke just now is themanager that I told you about.2. The pencil ________ ________ he was writing broke.3. Wu Dong; ________ ________ I went to the concert; enjoyed it very much.4. The two things ________ ________ Marx was not sure were the grammar and some of the idioms of English.5. Her bag; ________ ________ she put all her books; has not been found.6. The stories about the Long March; ________ ________ thisis one example; are well written.三、选择填空：1. The man ____ visited our school yesterday is from London.A. whoB. whichC. whomD. when2. The woman ____ is talking to my mother is a friend of hers.A. whoseB. whoC. whomD. which3. Because of my poor memory; all ____ you told me has been forgotten.A. thatB. whichC. whatD. as4. Do you remember those days ____ we spent along the seashore very happilyA. whenB. whereC. whichD. who5. Tom t took away the camera because it was just the samecamera ____ he lost last week.A. whichB. thatC. whomD. as6. Those ____ want to go please sign their names here.A. whomB. whichC. whoD. when7. Where is the man ____ I met this morningA. whenB. whereC. whichD. who8. Who is the woman ____ is sweeping the floor over thereA. whoB. /C. thatD. when9. The man ____ you talked just now is a worker.A. whoB. whomC. to whomD. to who10. The man ____ you are going to make friends is my father’s neighbour.A. with whomB. whenC. to whomD. which11. The doctor ____ is leaving for Africa next month.A. the nurse is talking to himB. whom the nurse is talkingC. the nurse is talking toD. who the nurse is talking12. The man ____ around our school is from America.A. which you showedB. you showed himC. you showedD. where you showed13. He talked about a hero ____ no one had ever heard.A. of whomB. from whomC. about thatD. who14. In fact the Swede did not understand the three questions____ were asked in French.A. whereB. whoC. in whichD. which15. Have you read the book ____ I lent to youA. thatB. whomC. whenD. whose16. Finally; the thief handed over everything ____ he had stolen to the police.A. thatB. whichC. whateverD. all17. The foreign guests; ____ were government officials; werewarmly welcomed at the airport.A. most of themB. most of thatC. most of whomD. most of those18. This is the very letter ____came last night.A. whoB. whichC. thatD. as19. I know only a little about this matter; you may ask ____ knows better than I.A. whoeverB. whomeverC. anyoneD. the one20. This is the school ____ we visited three days ago.A. whereB. /C. whenD. what21. This is the factory ____ we worked a year ago.A. whereB. thatC. whichD. on which22. Nearby were two canoes ____ they had come to the island.A. whichB. in whichC. thatD. /23. Jack is pleased with ____ you have given him and all ____ you have told him.A. that; whatB. what; thatC. which; whatD. that; which24. Do you work near the building ____ colour is yellowA. thatB. whichC. itsD. whose25. In the dark street; there wasn’t a single person ____ she could turn for help.A. whomB. whoC. to whomD. form whom26. Is this school ____ we visited three years agoA. the oneB. whichC. thatD. where27. Is this the school ____ we visited three years agoA. the oneB. whereC. in whichD. /28; How many students are there in your class ____ homes are in the countryA. whoseB. whoC. whomD. which29. Alice received an invitation from her boss; ____ cameas a surprise.A. itB. whichC. thatD. he30. The train was crowded and I had to get into a carriage____ already seven other people.A. when there wereB. which there wereC. that there wereD. where there were31. I live in the house ____ windows face south.A. whichB. whoseC. whereD. that32. ---- What game is popular with them---- The ____ most is tennis.A. game they like itB. game they likeC. best game they likeD. best game they like it33. They stayed with me three weeks; ____ they drank all the wine I had.A. whichB. which timeC. during whichD. during which time34. The room ____ Mr White lives is not very large.A. thatB. whichC. whereD. when35. Don’t forget the day ____ you were received into theYouth League.A. whenB. thatC. at whichD. where36. I’ve finished writing the novel; ____ is to be published next month.A. thatB. whatC. whichD. when37. He returned home safe and sound after a fierce battle; ____ was unexpected.A. whichB. asC. thatD. it38. ____ is known to all; English is not very difficult to learn.A. WhatB. AsC. ThatD. Which39. The old man had three sons; all of ____ died during World War Ⅱ.A. whoseB. thatC. whomD. who40. I have bought two pens; ____ write well.A. none of whichB. neither of whichC. both of whichD. all of which41. Do you know the reason ____ she has changed her mindA. whyB. whichC. for thatD. of which42. He failed in the exam; ____ proves that he wasn’t working hard enough.A. whichB. whatC. itD. that43. During the week ____ he tried to collect materials for his article.A. followingB. followedC. to followD. that followed44. ____ was expected; he succeeded in the exam.A. ItB. WhichC. AsD. That45. He studied hard and later became a well-known writer; ____ his father expected.A. that was whatB. what was thatC. and which wasD. which was what46. We should read such books ____ will make us better and wiser.A. whenB. asC. whoseD. what47. You must show my wife the same respect ____ you show me.A. whenB. asC. whoseD. what48. He is absent; ____ is often the case.A. whatB. whichC. whoD. as49. It is the first time ____ I have come to your city.A. thatB. whichC. whatD. when50. Who ____ has the same idea as it will do it in this way.A. whoB. thatC. whomD. which51. I shall never forget those years ____ I lived in thecountry with the farmers; ____ has a great effect on my life.A. that; whichB. when; whichC. which; thatD. when; who52. This is the only book ____ I can find.A. thatB. whichC. itD. with which53. I don’t like ____ you speak to her.A. the wayB. the way in thatC. the way whichD. the way of which54. That is one of those books that ____ worth reading.A. isB. areC. hasD. have55. This is the only one of the students whose handwriting ____ the best.A. isB. areC. hasD. have定语从句参考答案一、1. The fan that you want is on the desk.2. The man who brought our textbooks here yesterday is in next room.3. The magazine which he has taken away is mine.4. The students who don’t study hard will not pass the exam.5. The woman you saw in the park is our geography teacher.6. The letter I received yesterday is from my sister.7. The play that we saw last night was wonderful.8. The train which was going to Nanning was late.9. The boy who was here a minute ago is my brother.10. The tree he is climbing is quite tall.11. Here is the girl whose brother works in this shop.12. That’s the child whose drawing we were looking at just now.13. This is the boy whose sister is a favous singer.14. I want to talk to the boy whose homework hasn’t beenhanded in.15. Is that the woman whose daughter is in my class16. He used to live in a big house; in front of which grew many banana trees.17. They passed a factory; at the back of which there were rice fields.18. The soldier ran to the building; on the top of which flewa flag.19. In the evening they arrived at a hill; at the foot of which there was a temple.20. She came into a big room; in the middle of which stooda large table.二、1. to whom; 2. wiht which; 3. with whom;4. about which;5. in which;6. of which三、1~5 ABACD 6~10 CDCCA 11~15 CCADA 16~20 ACCAB21~25 ABBDC 26~30 ADABD 31~35 BBDCA 36~40 CABCC 41~45 AADCD 46~50 BBDAB 51. BAABA。
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导入练习11. —Is that the small company you often refer to?—Right, just the one _______ you know my father used to work for years.A.thatB. whichC. whereD. As2. —Where did they fi nish the experiment?—It was in the lab _______ was taken charge of by Prof. Smith.A. whereB. /C. whichD. in which3. Examination compositions, together with most business letters and government reports, are the main situations _______ formal language is used.【A. in whichB. in thatC. of whichD. of that4. Which fi lm is the one _______ main actor has won the Best Actor Prize in the fi lm festival?A. whoB. whomC. whoseD. which5. In that country, November 30th is a national festival _______ everyone, men and women, old and young, sings and dances happily in the streets.A. whereB. whenC. thatD. as6. This is John Brown, _______ I think has something interesting to tell you.A. whichB. whomC. thatD. who7. We climbed the Huangshan Mountain yesterday, _______, not surprisingly, was crowded with visitors from all over the world.~A. whereB. whichC. thatD. when8. The famous football player, _______ a big party will be held tomorrow morning, is to arrive this afternoon.A. in honour of himB. in his honourC. in whose honourD. in which honour9. _______ was reported in the newspaper, seventeen passengers had been killed in the traffi c accident.A. ItB. AsC. WhatD. That10. The owner paid the worker $10 for tidying the whole building, most of _______ hadn’t been cleaned for at least a year.A. thatB. whatC. whenD. which11. He has made great contributions to the science of physics, _______ he was awarded the 2009 Nobel Prize."A. about whichB. whatC. for whichD. when12. I don’t want to use the same tool _______ you used yesterday to repair the air conditioner.A. itB. thatC. oneD. what13. They were interested _______ you told them.A. in whichB. in thatC. all thatD. in everything14. Is that the reason _______ you are in favor of the proposal?A. whichB. whatC. whyD. for that15. I have bought the same dress _______ she is wearing.~A. asB. thatC. whichD. what限制性定语从句提供有关主语或宾语的重要信息，起限定作用，与被修饰部分的关系紧密，如果省略该从句会使主句语义表达不完整。
例如：This is the very person that is wanted by the police.He is the man who /that lives next door.非限制性定语从句只是用来对被修饰部分作补充性的说明，与先行词关系比较松散，先行词与从句间可以用逗号隔开，从句可略去：The minister, who is to visit our university, is said to be a Qinghua University graduate.The businessman, whose suitcase has been found by a stranger, has left for Beijing.如果定语从句的先行词是专有名词或是带有形容词性物主代词(my, his, etc)或形容词性指示代词(this, that, etc)作限定词的名词词组，其后的定语从句通常为非限制性的。
例如：￥My mother, who has been on a visit to Australia, will fly back tomorrow..限制性定语从句的先行词只能是名词，代词或名词性词组，而非限制性定语从句的先行词除了是名词及名词性词组外，还可能是句子的一部分或是整个句子。
例如：They say he plays truant, which he doesn’t. [which指代plays truant]The meeting was put off till next month, as we hoped. [as指前面的句子]下面的表格归纳了前面已提到的两者不同之处：表一：限制性定语从句与非限制性定语从句的区别》as的用法1、as引导限制性定语从句时，常与such或the same连用，构成the same…as; such…as结构，as用于代替指人或物的先行词。
例如：I have never eaten such tasty foods as she cooked me.试比较the same…as和the same…that：This is the same book as I read last week.（这和我上周读的那本书是一样的。
）This is the same book that I read last year.（这就是我上周读的那本书。
）如果先行词表示抽象概念，则没有这种区别，例如：She told me the same story as/that she had told you.！在as／so…as结构中，后面的as也是关系代词，例如：We took as many men as could be permitted to attend the meeting.2、引导非限制性定语从句关系代词as引导非限制性定语从句时，用于代替整个主句，意思是“正如”，相当于and this或and that。
as从句位置较之which引导的非限制性定语从句更加灵活，因而as从句既可以指前面提到的内容，也可以指后面将要提到的内容，which一般在主句后。
例如：The test is cancelled, as you have hoped.The test, as you have hoped, is cancelled.▲注：as代表前面的整个主句并在从句中做主语时表达的意思应与主句一致，而且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.例如：He failed to pass the exam again, as is predicted.；He failed to pass the exam again, which annoyed his mother greatly.记住以下的as结构：as is known to all (众所周知)，as is often the case (情况常常如此)，as the name Indicates／suggests (顾名思义)，as may be imagined (可以想象得出)，as often happens (这种情况常常发生)，as has been said before (如前所述)，as has been pointed out (正如已经指出的)，as will be shown in ( 将在…中指出)，as is hoped ( 正如所希望的)3 介词+ 关系代词“介词+ 关系代词”引导的定语从句既可以是限制性定语从句，又可以是非限制性定语从句，“介词+关系代词”在从句中做主语、宾语、状语、定语等，介词的选择则要根据它与其先行词的关系或前后名词、动词等的搭配关系来决定，同时还应该考虑句子在上下文中要表达的意思。
4.“介词+ which／whom／whose”这时应注意介词与句中短语的搭配。
例如：The problem with which I have trouble has now been solved.-介词放在关系代词之前的形式的定语从句较之将介词至于从句之末的定语从句正式，因此多用于书面语当中，但在口语中有时也会出现；或者将介词后置，或在介词后置后用that（人、物）／who（人）代替which／whom，并且that可省略。
例如；Can you lend me a pen or pencil with which I can write?Can you lend me a pen or pencil that/ which I can write with?5.“介词+ which + 名词”引导的定语从句which是一个代表所有关系的关系代词，可用来代表一个名词／代词或句子的一部分，但更多地是来代表整个句子。