英语中的各种从句详解

1、从句一.名词性从句在句子中起名词作用的各种从句统称为名词性从句。这类从句在句中可担任主语、表语、宾语和同位语，名词从句可以分为主语从句、表语从句、宾语从句和同位语从句。1 .主语从句在句子中担当主语的是一个句子，这个从句就叫作主语从句。主语从句可以由下列连词、连接代词和连接副词引导，且不能省略。连词：that, whether连接代词： what, whatever, who, whoever 等连接副词： when, where, how, why(1)由连词that, whether引导的主语从句连词that, whether在从句中的作用只是引导主语从句，它在从句中不担任成分，不能省略，

2、且由that, whether引导的主语从句，多用it多形式主语e.g That the earth is round is true.=It is true that the earth is round.地球是圆的, 是一个事实。Whether he ' ll come or not hasn ' t been decided.= It hasn ' t been deddme wh note r he' ll(2)由连接代词或连接副词引导的主语从句连接代词who, which和连接副词 when, where, how, why都可以引导主语从句，它们分别

3、在从句中担任主语、宾语和状语，不能省略，翻译时，不能把它们译为疑问句，由它们引导的主语从句，也可以用形式主语it引导e.g Who let out the news remained unknown. =It remained unknown who let out the news. 谁泄漏了个消息仍 旧无人知道。When we' ll start is not clear=It is not clear when we'我KstOr时出发还不清楚。(3)以关系代词 what, whatever, whoever, whomever, whichever引导的主语从句不能用形

4、式主语it引导，它们在句子中担任成分，不能省略，语序为陈述语序。e.g What he said at the meeting is important.他在会上所说的事情是重要的。Whoever leaves the office should tell me.无论是谁离开办公室者|应该告诉我。(4)用it作形式主语的主语从句结构a. It is +名词+从句It is a fact that 事实是It is good news that,是好消,息It is a question that是个问题It is common knowledge that是常识类似的名词还有：a pity；

5、a wonder； a good thing； no wonder； surprise等。例如:It is a mystery to me how it all happened.这一切是怎么发生的是个谜。It is common knowledge that the whale is not a fish.鲸鱼不是鱼，这是常识。It is no surprise that Bob should have won the game.鲍勃会赢得这场比赛，这不足为奇。b. It is +形容词+从句It is necessary that 有必要It is clear that 很清楚It is

6、likely that 很可能It is important that重要的是 类似的形容词还有：strange; natural; obvious; true; good; wonderful; possible; unlikely; quite; unusual; certain;evident; worth-while; surprising; interesting; astonishing, etc.例如：It is obvious that conductors and insulators are both important in industry.很明显导体和绝缘体在工业中都

7、很重要。It is doubtful whether she will be able to come.她是否能来令人怀疑。It was really astonishing that he refused to talk to you .他拒绝和你说话真是令人惊讶。It is essential that he should be here by the weekend .周末之前，他应该到这里是必要的。It seems obvious that we can not go on like this.很明显我们不能这样下去了。c. It is +过去分词+从句It is said that

8、据说It is reported that据报_道It has been proved that 已证明 It must be proved that必须指出 类似的过去分词还有： known; estimated; expected; believed; thought; hoped; noted; discussed; required; decided;suggested; demanded; made clear; found out,etc.例如:It is thought that he is the best player.大家都认为他是最好的选手。It is estimated

9、 that the vase is 2000 years old.据估计这个花瓶有2000年的历史。It is used to be thought that a new star must be due to a collision between two stars. 过去一直认为新星是由于两颗星星之间碰撞产生的。It has not been made clear when the new road is to be opened to traffic.还没弄清楚这条路将开始通车。d. It +不及物动词+从句It seems that 好像是It happened that 碰巧It

10、follows that 由此可见It has turned out that 结果是类似的不及物动词还有：seem, appear, occur, follow, happen, turn out, etc.例如：It turned out that nobody remembered the address.结果是无人记得那个地址。It now appears that they are in urgent need of help.看起来他们急需帮助。It does not matter if I missed my train, because there is another lat

11、er.没有赶上这趟火车没有关系，稍晚还有一趟。It happened that I saw him yesterday.碰巧我昨天看见他了。当及物动词+宾语”较短时，也可用这种结构。例如:It shocked me that Peter did not tell anybody where he was.让我吃惊的是彼得没有告诉任何人他在哪里。It does not interest me whether you go or not.我对你去不去不感兴趣。e. It +某些固定结构+主语从句。It doesn ' t matter是无关紧要的It makes no difference

12、毫无区别It doesn ' t make too much difference that关系不大It doesn ' t need to be bothered - that不必担忧例如：It does not make any difference whether it rains or not .下不下雨没什么分别。It does not make the least difference to me what you do.对我来说你做什么都无关紧要。2 .宾语从句用作宾语的从句叫宾语从句。1 .引导宾语从句的关联词有三类：(1)从属连词that。如：He told

13、us that he felt ill.他对我们说他感到不舒服。I know he has returned. 我知道他已经回来了。注：that在引导宾语从句时也并不是任何情况下都可以省略。在以下情况下，that不能省略。1. Everybody could see what happened and that Tom was frightened. 大家者B会看出所发生的事情并知道Tom非常害怕。and连接两个宾语从句，that宾语从句放在and的后面时，that不能省略。2. I know nothing about him except that he is from the south

14、. 对他我无所知，只知道他是南方人。that引导的宾语从句作介词宾语时，that不能省略。3. That he ever said such a thing I simply don ' t believe.我简直不相信他曾说过这样的话。that从句位于句首时，that不可省略。4. We decided, in view of his special circumstances, that we would admit him for a probationary period. 鉴于他 的特殊情况，我们决定应允他一段试用期。主句谓语动词与that从句之间有插入语，that不可省略。

15、(2)从属连词if/whether。如：I doubt whether he will succeed.我怀疑他是否会成功。I don' t know if you can help me.我不知道你能否帮助我。(3)连接代词 who, whom, whose, what, which, whoever, whatever, whichever连接副词 where, when, how, why。e.g Who or what he was, Martin never learned.他是什么人？他是干什么的？马丁根本不知道。I wonder what he s writing to

16、me about.我不知道他要给我写信说什么事。I 'll tell you why I asked you to come. 我会告诉你我为什么要你来。2 .介词宾语从句宾语从句也可用作介词的宾语。如：He was deeply displeased by what had occurred that day 他对那天发生的事感至 U彳艮不快。I walked over to where she sat.我走向她坐的地方。有时介词可以省略。如：I don't care (for) who marries him.我不管谁跟他结婚。Be careful (as to) how

17、you do that. 你要注意做这件事的方式 .注意：连词that引导的名词性从句很少作介词的宾语，只用在 except, but, in后。其他一些介词的宾语从句 如果由连词that引导，则需用it先行一步，作形式宾语。如：He is a good student except that he is careless他是个好学生, 只是有点粗心。You may rely on it that I shall help you.你可以指望我会帮助你的3 .动词十it+that结构如果宾语从句后还有宾语补足语，则用it作形式宾语，而将宾语从句后置。如：We thought it strang

18、e that Xiao Wang did not come yesterday.我们认为小王昨天没来是奇怪的。He has made it clear that he will not give in.他已表明他不会屈服。4 .某些形容词或过去分词后常接宾语从句，这类形容词或过去分词有sure, glad, certain, pleased, happy,afraid, surprised, satisfied 等，连词 that 可省略。如：I am not sure what I ought to do.我不能确定我该做什么。I' m afraid you don ' t

19、understandsahda恐怕你没领会我说的意思。I' m surprised that I didn ' t see all thafbefore.我以前没看到过。5 .连词whether ( - or not)或if引导的宾语从句if和whether引导的宾语从句可以互换使用，但 whether常和or not连用,if 一般不与or not连用。如：I wonder whether it is true or not. 我不知它是真是假。用if引导宾语从句如果会引起歧义，应避免使用 if而用whethero试比较：Please let me know if you w

20、ant to go.Please let me know whether you want to go.(if从句可理解为宾语从句，意为“请告诉我你是否想去”；此句又可理解为条件状语从句意为“如果你想去的话，请告诉我一声”。)6 .宾语从句的否定转移。 在think, believe, suppose, expect等动词后的宾语从句，有时谓语尽管是否定意思， 却不用否定形式，而将think等动词变为否定形式。如：I don't think you are right. 我认为你错了。I don ' t believe they have finished their work

21、 yet我相信他们还未完成他们的工作。.3 .表语从句表语从句放在连系动词之后，充当复合句中的表语，一般结构是“主语十连系动词十表语从句”。可接表语从句的连系动词有 be, look , seemi, sound, appear等。如：China is no longer what she used to be.今日的中国不再是过去的中国了。The question remains whether they will be able to help us.问题还是他们能否帮我们。At that time , it seemed as if I couldn't think of the

22、 right word. 当时，我似乎怎么也想不出一个恰当的字眼来。引导表语从句的关联词的种类：(1)从属连词thate.g The trouble is that I have lost his address.麻烦是我把他的地址丢了。that是连词，没有词义，在句中不作成分，因此一般不可省略(但在口语中有时that可省略)。(2)从属连词 whether, as, as if / though引导的表语从句。如：He looked just as he had looked ten years before他看起来还与十年前一样。It sounds as if someone is kno

23、cking at the door.听起来好像有人在敲门。because, why引导的表语从句。如：That's because he didn't understand me那是因为他没有理解我( That's because 强调原因)That's why he got angry with me.那正是他对我生气的原因。(That's why 强调结果)注意：表示结果或名词 reason作主语时，后面的表语从句表示原因时要用that引导，不宜用because.如：The reason why I was sad was that he didn&

24、#39;t understand me.t过的原因是他没有理解我。(4)连接代词 who, whom, whose, what, which , whoever, whatever, whichever连接副词 where, when, how, whye.g The problem is who we can get to replace her.问题是我们能找到谁去替换她呢。The question is how he did it.问题是他是如何做此事的。That was what she did this morning on reaching the attic. 那就是她今晨上了

25、阁楼干的。(5)使用虚拟语气的表语从句在表示建议、劝告、命令含义的名词后的表语从句，谓语动词需用"should动词原形"表示,should可省略。 常见的词有： advice, suggestion, order, proposal, plan, idea 等。e.g My suggestion is that we (should) start early tomorrow. 我的建议是我们明天早就出发。4 .同位语从句英语中有一些名词如 fact, idea, news, word, hope, promise, suggestion, reply, problem,

26、belief, doubt, truth, order, thought等，它们本身有一定的意义，但表达得不够具体。为了使其表达的意义更加具体明确，其后常跟有 一个从句，用来补充说明该名词的内容，这个从句就叫做同位语从句。(1)同位语从句的引导词表示陈述意义时通常用that。注意that不能省略。同位语从句说明的名词常见的有：ability, advice, answer, belief, doubt, discovery, fact, fear, hope, idea,information, message, news, order, possibility, problem, propo

27、sal, question, story, suggestion, theory, thought, word(消息)等，同位语从句一般都是用来解释说明一些抽象名词，而不可说明的名词是不会接同位语从句的。比如：man, water, sun等具体的人或事物。e.g There is no doubt that the prices of cars will go down.The belief that the company will make a great is shared by everyone.表示“是否”的意思时只能用whether,不能用if。这一点与主语从句相似。e.g Th

28、e question whether he can finish the work within two days remains unknown.表示疑问时也可用其他引导词where, when, why, how, who, what来引导。e.g This student asked a good question why pollution can' t be stopped.I have no idea where I should go.I have no idea how I can get to the railway station.（2）同位语从句和定语从句的区别定

29、语从句相当于一个形容词，它对先行词起修饰、描述和限制的作用。同位语从句相当于名词，属于名 词性从句，它是对前面名词内容的具体表述，它们之间的关系是同位关系。试比较：The news that you heard is not true.你听到的那个消息不是真的。（定语从句）The news that he has died is true.他已经去世的消息是真的。（同位语从句，说明了 news的具体内容，即hehas died） 同位语从句常是艮在news, fact, promise, idea, word, message, hope, truth, answer, proposal, s

30、uggestion, order,information等少数名词之后，而一般名词之后都可跟定语从句。e.g He didn ' t give the answer why he was 1ate没回答他为什么迟到这个问题。（同位语从句）Then rose a question where we should go.于是产生了一个问题：我们该到哪里去？（同位语从句）that在定语从句中充当某一成分，是关系代词；that在同位语从句中不作任何成分，仅把主句与从句连 接在一起，是从属连词。如：The fact that just now you talked about interests

31、 me.你们刚才谈论的事情使我感兴趣。（定语从句）The fact that he failed in the exam made his parents very angry.他考试没及格这个事实使他的父母很生气。（同位语从句）when, where, why, how, who, whom, which如果引导定语从句，它们分别指前面先行词所表示的时间、地点、原因、方式、人和物，否则引导的就是同位语从句。试比较：I still remember the day when he was killed.我还记得他被害的那一天。（定语从句）I have no idea when he was k

32、illed.我不知道他什么时候被害的。（同位语从句）They didn't go to the town where they were born.他们没有去他们出生的小镇。（定语从句）They didn't answer the question where they were born.他们没有回答他们在哪里出生这个问题。（同位语从句）whether, what可引导同位语从句，但通常不可引导定语从句。e.g We have no information whether he is alive.我们不知道他是否活着。（同位语从句）Next comes the questio

33、n what step we should take.接着的问题是我们下一步该做什么。（同位语从句）二.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，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 等。关系副词有： when, where, why 等。1 .关系代词引导的定语从句关系代词所代替的先行词是人或物的名词或代词，并在句中充当主语、宾语、定语等成分。关系代词在定 语从句中作主语时，从句谓语动词的人称和数要和先行词保

34、持一致。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：e.g Is he the man who/that wants to see you?ftk就是你想见的人吗？ ( who/that 在从句中作主语)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)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)。e.g They rushed over to help the man whose car had broken

35、down.那人车坏了, 大家者|跑过去帮，忙。Please pass me the book whose (of which) cover is green. 请递给我那本绿皮的书。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 prosperitywhich / that had never been seen before appears in the countryside. 农村出现了前所未有的繁荣。 (which / that 在句中作宾语)The package (which / that) you are carrying i

36、s about to come unwrapped. 你拿的包快散了。(which / that 在句中作宾语)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、地点或理由的名词，在从句中作状语。1)when, where, why关系副词when, where, why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.e.g There are occasions when (on which) one must yield.任何人都有不得不屈服的时候。Beijing is the place where (in wh

37、ich) I was born.北京是我的出生地。Is this the reason why (for which) he refused our offer?这就是他拒绝我们帮助他的理由吗？2 ) that代替关系副词that可以用于表示时间、地点、方式、理由的名词后取代 when, where, why和"介词+ which"引导的定语从 句，在口语中that常被省略.e.g His father died the year (that / when / in which) he was born. 他父亲在他出生 年逝世了。He is unlikely to fin

38、d the place (that / where / in which) he lived forty years ago. 他不大可能找至 U他四十年前居住过的地方。3 .判断关系代词与关系副词方法一：用关系代词，还是关系副词完全取决于从句中的谓语动词。及物动词后面无宾语，就必须要求用 关系代词；而不及物动词则要求用关系副词。例如：This is the mountain village where I stayed last year.I'll never forget the days when I worked together with you.判断改错（注：先显示题，再显

39、示答案，横线；用不同的颜色表示出。）（错） This is the mountain village where I visited last year.（错） I will never forget the days when I spent in the countryside.（对） This is the mountain village （which） I visited last year.（对） I'll never forget the days （which） I spent in the countryside.习惯上总把表地点或时间的名词与关系副词where, w

40、hen联系在一起。此两题错在关系词的误用上。方法二：准确判断先行词在定语从句中的成分（主、谓、宾、定、状），也能正确选择出关系代词/关系副词。例 1. Is this museum you visited a few days ago?A. where B. that C. on which D. the one例 2. Is this the museum the exhibition was held ?A. where B. that C. on which D. the one答案：例1 D,例2 A例 1 变为肯定句：This museum is you visited a few

41、days ago.例 2 变为肯定句：This is the museum the exhibition was held.在句1中，所缺部分为宾语，而 where, that, on which都不能起到宾语的作用，只有 the one既做了主句 的表语，又可做从句的宾语，可以省略关系代词，所以应选 D。而句2中，主、谓、宾俱全，从句部分为句子的状语表地点，既可用副词where,又因in the museum词组，可用介词in + which引导地点状语。而此题中，介词on用的不对，所以选 A。关系词的选择依据在从句中所做的成分，先行词在从句中做主、定、宾语时，选择关系代词（who, who

42、m,that, which, whose）；先行词在从句中做状语时， 应选择关系副词 （where地点状语，when时间状语，why 原因状语）。4 .限制性和非限制性定语从句1）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。e.g This is the house which we bought last month.这是我们上个月买的那幢房子。（限制性）The house, which we bought last month, is very

43、 nice.这幢房子很漂亮,是我们上个月买 （非限制性）2）非限定性定语从句不能用that引导，一般用引导词 which / as或who （指人），非限定性定语从句既可以修饰主句的部分内容，也可彳饰主句的全部内容。as引导的非限定性定语从句既可以放在主句之前，也可以放在主句之后，但 which或who引导的非限定性定语从句不能放在主句句首。e.g As we all know, the moon is a satellite of the earth.The large area is covered with thick snow, which affects people's l

44、ife greatly.His speech, which bored us to death, was over at last.Her sister, who lived in another city, was coming to visit her.5 . as, which非限定性定语从句由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，也可以放在句中，which在句中。e.g As we know, smoking is harmful to one's health.The sun he

45、ats the earth, which is very important to us.典型例题1) Alice received an invitation from her boss,came as a surprise.A. it B. that C. which D. he答案C.此为非限定性从句，不能用that修饰，而用which., it和he都使后句成为句子，两个独立的句子不能单以逗号连接。况且选he句意不通。2) The weather turned out to be very good,was more than we could expect.A. what B. wh

46、ich C. that D. it答案Bo which可代替句子，用于非限定性定语从句，而what不可。That不能用于非限定性定语从句，it不为连词，使由逗号连接的两个句子并在一起在英语语法上行不通。3) It rained hard yesterday,prevented me from going to the park.A. that B. which C. as D. it答案B.as和which在引导非限制性定语从句时，这两个关系代词都指主句所表达的整个意思，且在定语从句中都可以作主语和宾语。但不同之处主要有两点：(1)as引导的定语从句可置于句首，而 which不可。(2)as代

47、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. o在本题中，prevent由于是行为动词，所以正确选项应为B。As的用法例1. the same as； such- as中的as是一种固定结构，和一样。I have got into the same trouble as he (has).例2. as可引导非限制性从句，常含有正如的意思。As we know, smoking is harmful to one's health.As is known, smoking is harmful to one's

48、health.As是关系代词。例1中的as作know的宾语；例2中，它充当从句的主语，谓语动词know要用被动式。6.介词+关系词1）介词后面的关系词不能省略。2） that前不能有介词。3）某些在从句中充当时间，地点或原因状语的"介词+关系词"结构可以同关系副词 when和where互换。 e.g This is the house in which I lived two years ago.This is the house where I lived two years ago.Do you remember the day on which you joined

49、our club?Do you remember the day when you joined our club?7.关系代词that的用法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 that we get our food.（错）改为： We depend on the land from which we get our food.We depend on the land th

50、at/which we get our food from.2）只能用that,不能用which作为定语从句的关系代词的情况当先行词是不定代词时 ，如:all, little, much, none, one, everyone, something, anything, everything, nothing 等。e.g That ' s all that I could do at that time.就是我那是所能为你做的全部。当先行词被 the only, the very, the same, little, few, no,等修饰时。e.g The only thing t

51、hat I can do is to have a rest.我唯一能做的事情就是休息。当先行词被序数词或形容词最高级修饰时。e.g He was the first person that passed the examination他是第个通过这个考试的人。This is the best way that can solve the problem.这是解决那个问题的最好办法。被修饰词为数词时，只能用 that。e.g Yesterday my mother bought two dogs. Now you can see the two that are playing over th

52、ere. 昨天我妈妈买了 两只狗。现在你能看见它们在那边玩。主句是there be结构，修饰其主语的定语从句thate.g There is a book on the desk that belongs to Jack桌上那本书是杰克的。主句是以which或who开头的特殊疑问句时，关系代词只能用that。e.g Who is the girl that is talking with Mr. Brown ?如果出现两个或两个以上的先行词，并同时兼指人和物时，关系代词用that。e.g We are talking about the people and countries that we

53、 have visited.如果两个从句，其中一个关系代词已用which,另一个关系代词应用that,以避免重复。e.g He built up a factory which produced things that had never been seen before.他办了一家工厂，生产过去从未见到的东西。三.状语从句副词性从句(状语从句)状语从句主要用来修饰主句或主句的谓语。一般可分为十大类，分别表示时间、地点、原因、目的、结果、 条件、让步、比较 、方式和程度。1 .时间状语从句(1)常用弓I导词： when, as, while, as soon as, before, after

54、, since , till, ( until )特殊弓I导词： the minute, the moment, the second, every time, the day, the instant, immediately , directly, no sooner than, hardly - when, scarcely whene.g I didn't realize how special my mother was until I became an adult.While John was watching TV , his wife was cooking.The

55、children ran away from the orchard (果园)the moment they saw the guard.when, while, as引导时间状语从句时的异同when引导的时间状语从句中的谓语动词既可以是延续性动词，也可以是短暂性动词；从句的动作可以和主句的动作同时发生，也可以先于主句的动作发生，此时相当于aftero当when从句谓语动词是延续性动词时，可与while互换。e.g I often missed my home a lot when I was abroad. ( =while )When they came home, I was cooki

56、ng dinner.(不能用 while)When the film ended, people rushed out of the hall. ( =after )when从句置于主句后面，同时从句中谓语动词又是短暂性动词时，常表示此时突然”。e.g I was walking along the street when I caught sight of a tailor' s shop.He was enjoying his dinner when a loud noise came on the door.while引导的动作必须是持续性的，强调主句和从句动作的同时发生，有时侧

57、重主句和从句动作的对比。He took a bath while I was preparing dinner.as常可与when, while通用，但它较强调主句和从句动作的同时发生，常译作 边边”也可用来说明 两种正在发展和变化的情况，此时常译作 随着”。e.g He sang happily as he walked along the path.The day gets longer and longer as summer comes.until, till引导的时间状语从句主句谓语动词为延续性动词时，主句和从句都用肯定句式，意为直到"，表示主句动作一直延续到until/till从句表示的时间才终止；主句谓语动词为短暂性动词时，主句用否定式，从句用肯定式，意思是-直到才”，表示主句动作到until/till从句表示的时间才开始。e.g He worked until/till it was dark.He didn ' t work until/till it was dark.until和till意义相同，通常可换用，但在强调结构、倒装句或句首，一般用