英语中的各种从句详解.doc

Four short words sum up what has lifted most successful individuals above the crowd: a little bit more.-author-date英语中的各种从句详解从句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，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 hell come or not hasnt been decided.= It hasnt been decided whether hell come or not.(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.谁泄漏了那个消息仍旧无人知道。 When well start is not clear. =It is not clear when well start.我们何时出发还不清楚。(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都应该告诉我。(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；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 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 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 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 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 later.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 doesnt matter是无关紧要的It makes no difference毫无区别It doesnt make too much difference that 关系不大It doesnt 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 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. 大家都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. 对他我一无所知，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 dont 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。(2)从属连词if/whether。如：I doubt whether he will succeed. 我怀疑他是否会成功。I dont 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 hes writing to me about. 我不知道他要给我写信说什么事。 Ill 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到很不快。 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 dont care (for) who marries him. 我不管谁跟他结婚。 Be careful (as to) how 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.他是一个好学生，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itthat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 strange 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。 Im afraid you dont understand what I said.恐怕你没领会我说的意思。 Im surprised that I didnt see all that before.我好奇怪，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whether。试比较： Please let me know if you want 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 dont think you are right. 我认为你错了。I dont believe they have finished their work 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“主语连系动词表语从句”。可接表语从句的连系动词有be，look，seem，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 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 knocking at the door.听起来好像有人在敲门。(3) 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't understand me.我难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一早就出发。4. 同位语从句英语中有一些名词如fact, idea, news, word, hope, promise, suggestion, reply, problem, 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, proposal, 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 The 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 cant 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he has died） 同位语从句常跟在 news, fact, promise, idea, word, message, hope, truth, answer, proposal, suggestion, 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 didnt give the answer why he was late. 他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 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 killed. 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 question 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?他就是你想见的人吗？（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 down.那人车坏了，大家都跑过去帮忙。 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 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在句中作宾语）The package (which / that) you are carrying is 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 which) 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.他父亲在他出生那年逝世了。He is unlikely to find the place (that / where / in which) he lived forty years ago. 他不大可能找到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, when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. whereB. that C. on which D. the one 例2. Is this the museum _ the exhibition was held？ A. whereB. that C. on whichD. the one 答案：例1 D，例2 A 例1变为肯定句： This museum is _ you visited a few 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, whom, 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 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，也可修饰主句的全部内容。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 life 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 heats 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. whichD. 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. whatB. whichC. thatD. it 答案B。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. thatB. whichC. 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.。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；suchas 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'