英語(yǔ)中的各種從句詳解

1、從句一.名詞性從句在句子中起名詞作用的各種從句統(tǒng)稱為名詞性從句。這類從句在句中可擔(dān)任主語(yǔ)、表語(yǔ)、賓語(yǔ)和同位語(yǔ)，名詞從句可以分為主語(yǔ)從句、表語(yǔ)從句、賓語(yǔ)從句和同位語(yǔ)從句。1 .主語(yǔ)從句在句子中擔(dān)當(dāng)主語(yǔ)的是一個(gè)句子，這個(gè)從句就叫作主語(yǔ)從句。主語(yǔ)從句可以由下列連詞、連接代詞和連接副詞引導(dǎo)，且不能省略。連詞：that, whether連接代詞： what, whatever, who, whoever 等連接副詞： when, where, how, why(1)由連詞that, whether引導(dǎo)的主語(yǔ)從句連詞that, whether在從句中的作用只是引導(dǎo)主語(yǔ)從句，它在從句中不擔(dān)任成分，不能省略，

2、且由that, whether引導(dǎo)的主語(yǔ)從句，多用it多形式主語(yǔ)e.g That the earth is round is true.=It is true that the earth is round.地球是圓的, 是一個(gè)事實(shí)。Whether he ' ll come or not hasn ' t been decided.= It hasn ' t been deddme wh note r he' ll(2)由連接代詞或連接副詞引導(dǎo)的主語(yǔ)從句連接代詞who, which和連接副詞 when, where, how, why都可以引導(dǎo)主語(yǔ)從句，它們分別

3、在從句中擔(dān)任主語(yǔ)、賓語(yǔ)和狀語(yǔ)，不能省略，翻譯時(shí)，不能把它們譯為疑問(wèn)句，由它們引導(dǎo)的主語(yǔ)從句，也可以用形式主語(yǔ)it引導(dǎo)e.g Who let out the news remained unknown. =It remained unknown who let out the news. 誰(shuí)泄漏了個(gè)消息仍 舊無(wú)人知道。When we' ll start is not clear=It is not clear when we'我KstOr時(shí)出發(fā)還不清楚。(3)以關(guān)系代詞 what, whatever, whoever, whomever, whichever引導(dǎo)的主語(yǔ)從句不能用形

4、式主語(yǔ)it引導(dǎo)，它們?cè)诰渥又袚?dān)任成分，不能省略，語(yǔ)序?yàn)殛愂稣Z(yǔ)序。e.g What he said at the meeting is important.他在會(huì)上所說(shuō)的事情是重要的。Whoever leaves the office should tell me.無(wú)論是誰(shuí)離開辦公室者|應(yīng)該告訴我。(4)用it作形式主語(yǔ)的主語(yǔ)從句結(jié)構(gòu)a. It is +名詞+從句It is a fact that 事實(shí)是It is good news that,是好消,息It is a question that是個(gè)問(wèn)題It is common knowledge that是常識(shí)類似的名詞還有：a pity；

5、a wonder； a good thing； no wonder； surprise等。例如:It is a mystery to me how it all happened.這一切是怎么發(fā)生的是個(gè)謎。It is common knowledge that the whale is not a fish.鯨魚不是魚，這是常識(shí)。It is no surprise that Bob should have won the game.鮑勃會(huì)贏得這場(chǎng)比賽，這不足為奇。b. It is +形容詞+從句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 類似的形容詞還有：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.很明顯導(dǎo)體和絕緣體在工業(yè)中都

7、很重要。It is doubtful whether she will be able to come.她是否能來(lái)令人懷疑。It was really astonishing that he refused to talk to you .他拒絕和你說(shuō)話真是令人驚訝。It is essential that he should be here by the weekend .周末之前，他應(yīng)該到這里是必要的。It seems obvious that we can not go on like this.很明顯我們不能這樣下去了。c. It is +過(guò)去分詞+從句It is said that

8、據(jù)說(shuō)It is reported that據(jù)報(bào)_道It has been proved that 已證明 It must be proved that必須指出 類似的過(guò)去分詞還有： 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.大家都認(rèn)為他是最好的選手。It is estimated

9、 that the vase is 2000 years old.據(jù)估計(jì)這個(gè)花瓶有2000年的歷史。It is used to be thought that a new star must be due to a collision between two stars. 過(guò)去一直認(rèn)為新星是由于兩顆星星之間碰撞產(chǎn)生的。It has not been made clear when the new road is to be opened to traffic.還沒(méi)弄清楚這條路將開始通車。d. It +不及物動(dòng)詞+從句It seems that 好像是It happened that 碰巧It

10、follows that 由此可見(jiàn)It has turned out that 結(jié)果是類似的不及物動(dòng)詞還有：seem, appear, occur, follow, happen, turn out, etc.例如：It turned out that nobody remembered the address.結(jié)果是無(wú)人記得那個(gè)地址。It now appears that they are in urgent need of help.看起來(lái)他們急需幫助。It does not matter if I missed my train, because there is another lat

11、er.沒(méi)有趕上這趟火車沒(méi)有關(guān)系，稍晚還有一趟。It happened that I saw him yesterday.碰巧我昨天看見(jiàn)他了。當(dāng)及物動(dòng)詞+賓語(yǔ)”較短時(shí)，也可用這種結(jié)構(gòu)。例如:It shocked me that Peter did not tell anybody where he was.讓我吃驚的是彼得沒(méi)有告訴任何人他在哪里。It does not interest me whether you go or not.我對(duì)你去不去不感興趣。e. It +某些固定結(jié)構(gòu)+主語(yǔ)從句。It doesn ' t matter是無(wú)關(guān)緊要的It makes no difference

12、毫無(wú)區(qū)別It doesn ' t make too much difference that關(guān)系不大It doesn ' t need to be bothered - that不必?fù)?dān)憂例如：It does not make any difference whether it rains or not .下不下雨沒(méi)什么分別。It does not make the least difference to me what you do.對(duì)我來(lái)說(shuō)你做什么都無(wú)關(guān)緊要。2 .賓語(yǔ)從句用作賓語(yǔ)的從句叫賓語(yǔ)從句。1 .引導(dǎo)賓語(yǔ)從句的關(guān)聯(lián)詞有三類：(1)從屬連詞that。如：He told

13、us that he felt ill.他對(duì)我們說(shuō)他感到不舒服。I know he has returned. 我知道他已經(jīng)回來(lái)了。注：that在引導(dǎo)賓語(yǔ)從句時(shí)也并不是任何情況下都可以省略。在以下情況下，that不能省略。1. Everybody could see what happened and that Tom was frightened. 大家者B會(huì)看出所發(fā)生的事情并知道Tom非常害怕。and連接兩個(gè)賓語(yǔ)從句，that賓語(yǔ)從句放在and的后面時(shí)，that不能省略。2. I know nothing about him except that he is from the south

14、. 對(duì)他我無(wú)所知，只知道他是南方人。that引導(dǎo)的賓語(yǔ)從句作介詞賓語(yǔ)時(shí)，that不能省略。3. That he ever said such a thing I simply don ' t believe.我簡(jiǎn)直不相信他曾說(shuō)過(guò)這樣的話。that從句位于句首時(shí)，that不可省略。4. We decided, in view of his special circumstances, that we would admit him for a probationary period. 鑒于他 的特殊情況，我們決定應(yīng)允他一段試用期。主句謂語(yǔ)動(dòng)詞與that從句之間有插入語(yǔ)，that不可省略。

15、(2)從屬連詞if/whether。如：I doubt whether he will succeed.我懷疑他是否會(huì)成功。I don' t know if you can help me.我不知道你能否幫助我。(3)連接代詞 who, whom, whose, what, which, whoever, whatever, whichever連接副詞 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？馬丁根本不知道。I wonder what he s writing to

16、me about.我不知道他要給我寫信說(shuō)什么事。I 'll tell you why I asked you to come. 我會(huì)告訴你我為什么要你來(lái)。2 .介詞賓語(yǔ)從句賓語(yǔ)從句也可用作介詞的賓語(yǔ)。如：He was deeply displeased by what had occurred that day 他對(duì)那天發(fā)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。有時(shí)介詞可以省略。如：I don't care (for) who marries him.我不管誰(shuí)跟他結(jié)婚。Be careful (as to) how

17、you do that. 你要注意做這件事的方式 .注意：連詞that引導(dǎo)的名詞性從句很少作介詞的賓語(yǔ)，只用在 except, but, in后。其他一些介詞的賓語(yǔ)從句 如果由連詞that引導(dǎo)，則需用it先行一步，作形式賓語(yǔ)。如：He is a good student except that he is careless他是個(gè)好學(xué)生, 只是有點(diǎn)粗心。You may rely on it that I shall help you.你可以指望我會(huì)幫助你的3 .動(dòng)詞十it+that結(jié)構(gòu)如果賓語(yǔ)從句后還有賓語(yǔ)補(bǔ)足語(yǔ)，則用it作形式賓語(yǔ)，而將賓語(yǔ)從句后置。如：We thought it strang

18、e that Xiao Wang did not come yesterday.我們認(rèn)為小王昨天沒(méi)來(lái)是奇怪的。He has made it clear that he will not give in.他已表明他不會(huì)屈服。4 .某些形容詞或過(guò)去分詞后常接賓語(yǔ)從句，這類形容詞或過(guò)去分詞有sure, glad, certain, pleased, happy,afraid, surprised, satisfied 等，連詞 that 可省略。如：I am not sure what I ought to do.我不能確定我該做什么。I' m afraid you don ' t

19、understandsahda恐怕你沒(méi)領(lǐng)會(huì)我說(shuō)的意思。I' m surprised that I didn ' t see all thafbefore.我以前沒(méi)看到過(guò)。5 .連詞whether ( - or not)或if引導(dǎo)的賓語(yǔ)從句if和whether引導(dǎo)的賓語(yǔ)從句可以互換使用，但 whether常和or not連用,if 一般不與or not連用。如：I wonder whether it is true or not. 我不知它是真是假。用if引導(dǎo)賓語(yǔ)從句如果會(huì)引起歧義，應(yīng)避免使用 if而用whethero試比較：Please let me know if you w

20、ant to go.Please let me know whether you want to go.(if從句可理解為賓語(yǔ)從句，意為“請(qǐng)告訴我你是否想去”；此句又可理解為條件狀語(yǔ)從句意為“如果你想去的話，請(qǐng)告訴我一聲”。)6 .賓語(yǔ)從句的否定轉(zhuǎn)移。 在think, believe, suppose, expect等動(dòng)詞后的賓語(yǔ)從句，有時(shí)謂語(yǔ)盡管是否定意思， 卻不用否定形式，而將think等動(dòng)詞變?yōu)榉穸ㄐ问?。如：I don't think you are right. 我認(rèn)為你錯(cuò)了。I don ' t believe they have finished their work

21、 yet我相信他們還未完成他們的工作。.3 .表語(yǔ)從句表語(yǔ)從句放在連系動(dòng)詞之后，充當(dāng)復(fù)合句中的表語(yǔ)，一般結(jié)構(gòu)是“主語(yǔ)十連系動(dòng)詞十表語(yǔ)從句”?？山颖碚Z(yǔ)從句的連系動(dòng)詞有 be, look , seemi, sound, appear等。如：China is no longer what she used to be.今日的中國(guó)不再是過(guò)去的中國(guó)了。The question remains whether they will be able to help us.問(wèn)題還是他們能否幫我們。At that time , it seemed as if I couldn't think of the

22、 right word. 當(dāng)時(shí)，我似乎怎么也想不出一個(gè)恰當(dāng)?shù)淖盅蹃?lái)。引導(dǎo)表語(yǔ)從句的關(guān)聯(lián)詞的種類：(1)從屬連詞thate.g The trouble is that I have lost his address.麻煩是我把他的地址丟了。that是連詞，沒(méi)有詞義，在句中不作成分，因此一般不可省略(但在口語(yǔ)中有時(shí)that可省略)。(2)從屬連詞 whether, as, as if / though引導(dǎo)的表語(yǔ)從句。如：He looked just as he had looked ten years before他看起來(lái)還與十年前一樣。It sounds as if someone is kno

23、cking at the door.聽起來(lái)好像有人在敲門。because, why引導(dǎo)的表語(yǔ)從句。如：That's because he didn't understand me那是因?yàn)樗麤](méi)有理解我( That's because 強(qiáng)調(diào)原因)That's why he got angry with me.那正是他對(duì)我生氣的原因。(That's why 強(qiáng)調(diào)結(jié)果)注意：表示結(jié)果或名詞 reason作主語(yǔ)時(shí)，后面的表語(yǔ)從句表示原因時(shí)要用that引導(dǎo)，不宜用because.如：The reason why I was sad was that he didn&

24、#39;t understand me.t過(guò)的原因是他沒(méi)有理解我。(4)連接代詞 who, whom, whose, what, which , whoever, whatever, whichever連接副詞 where, when, how, whye.g The problem is who we can get to replace her.問(wèn)題是我們能找到誰(shuí)去替換她呢。The question is how he did it.問(wèn)題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、閣樓干的。(5)使用虛擬語(yǔ)氣的表語(yǔ)從句在表示建議、勸告、命令含義的名詞后的表語(yǔ)從句，謂語(yǔ)動(dòng)詞需用"should動(dòng)詞原形"表示,should可省略。 常見(jiàn)的詞有： advice, suggestion, order, proposal, plan, idea 等。e.g My suggestion is that we (should) start early tomorrow. 我的建議是我們明天早就出發(fā)。4 .同位語(yǔ)從句英語(yǔ)中有一些名詞如 fact, idea, news, word, hope, promise, suggestion, reply, problem,

26、belief, doubt, truth, order, thought等，它們本身有一定的意義，但表達(dá)得不夠具體。為了使其表達(dá)的意義更加具體明確，其后常跟有 一個(gè)從句，用來(lái)補(bǔ)充說(shuō)明該名詞的內(nèi)容，這個(gè)從句就叫做同位語(yǔ)從句。(1)同位語(yǔ)從句的引導(dǎo)詞表示陳述意義時(shí)通常用that。注意that不能省略。同位語(yǔ)從句說(shuō)明的名詞常見(jiàn)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，同位語(yǔ)從句一般都是用來(lái)解釋說(shuō)明一些抽象名詞，而不可說(shuō)明的名詞是不會(huì)接同位語(yǔ)從句的。比如：man, water, sun等具體的人或事物。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”的意思時(shí)只能用whether,不能用if。這一點(diǎn)與主語(yǔ)從句相似。e.g Th

28、e question whether he can finish the work within two days remains unknown.表示疑問(wèn)時(shí)也可用其他引導(dǎo)詞where, when, why, how, who, what來(lái)引導(dǎo)。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）同位語(yǔ)從句和定語(yǔ)從句的區(qū)別定

29、語(yǔ)從句相當(dāng)于一個(gè)形容詞，它對(duì)先行詞起修飾、描述和限制的作用。同位語(yǔ)從句相當(dāng)于名詞，屬于名 詞性從句，它是對(duì)前面名詞內(nèi)容的具體表述，它們之間的關(guān)系是同位關(guān)系。試比較：The news that you heard is not true.你聽到的那個(gè)消息不是真的。（定語(yǔ)從句）The news that he has died is true.他已經(jīng)去世的消息是真的。（同位語(yǔ)從句，說(shuō)明了 news的具體內(nèi)容，即hehas died） 同位語(yǔ)從句常是艮在news, fact, promise, idea, word, message, hope, truth, answer, proposal, s

30、uggestion, order,information等少數(shù)名詞之后，而一般名詞之后都可跟定語(yǔ)從句。e.g He didn ' t give the answer why he was 1ate沒(méi)回答他為什么遲到這個(gè)問(wèn)題。（同位語(yǔ)從句）Then rose a question where we should go.于是產(chǎn)生了一個(gè)問(wèn)題：我們?cè)摰侥睦锶?？（同位語(yǔ)從句）that在定語(yǔ)從句中充當(dāng)某一成分，是關(guān)系代詞；that在同位語(yǔ)從句中不作任何成分，僅把主句與從句連 接在一起，是從屬連詞。如：The fact that just now you talked about interests

31、 me.你們剛才談?wù)摰氖虑槭刮腋信d趣。（定語(yǔ)從句）The fact that he failed in the exam made his parents very angry.他考試沒(méi)及格這個(gè)事實(shí)使他的父母很生氣。（同位語(yǔ)從句）when, where, why, how, who, whom, which如果引導(dǎo)定語(yǔ)從句，它們分別指前面先行詞所表示的時(shí)間、地點(diǎn)、原因、方式、人和物，否則引導(dǎo)的就是同位語(yǔ)從句。試比較：I still remember the day when he was killed.我還記得他被害的那一天。（定語(yǔ)從句）I have no idea when he was k

32、illed.我不知道他什么時(shí)候被害的。（同位語(yǔ)從句）They didn't go to the town where they were born.他們沒(méi)有去他們出生的小鎮(zhèn)。（定語(yǔ)從句）They didn't answer the question where they were born.他們沒(méi)有回答他們?cè)谀睦锍錾@個(gè)問(wèn)題。（同位語(yǔ)從句）whether, what可引導(dǎo)同位語(yǔ)從句，但通常不可引導(dǎo)定語(yǔ)從句。e.g We have no information whether he is alive.我們不知道他是否活著。（同位語(yǔ)從句）Next comes the questio

33、n what step we should take.接著的問(wèn)題是我們下一步該做什么。（同位語(yǔ)從句）二.定語(yǔ)從句定語(yǔ)從句(Attributive Clauses)在句中做定語(yǔ)，修飾一個(gè)名詞或代詞，被修飾的名詞，詞組或代詞即先行詞。定語(yǔ)從句通常出現(xiàn)在先行詞之后，由關(guān)系詞(關(guān)系代詞或關(guān)系副詞)引出。關(guān)系代詞有： who, whom, whose, that, which 等。關(guān)系副詞有： when, where, why 等。1 .關(guān)系代詞引導(dǎo)的定語(yǔ)從句關(guān)系代詞所代替的先行詞是人或物的名詞或代詞，并在句中充當(dāng)主語(yǔ)、賓語(yǔ)、定語(yǔ)等成分。關(guān)系代詞在定 語(yǔ)從句中作主語(yǔ)時(shí)，從句謂語(yǔ)動(dòng)詞的人稱和數(shù)要和先行詞保

34、持一致。1) who, whom, that這些詞代替的先行詞是人的名詞或代詞，在從句中所起作用如下：e.g Is he the man who/that wants to see you?ftk就是你想見(jiàn)的人嗎？ ( who/that 在從句中作主語(yǔ))He is the man whom/ that I saw yesterday.他就是我昨天見(jiàn)的那個(gè)人。(whom/that在從句中作賓語(yǔ))2) Whose用來(lái)指人或物，(只用作定語(yǔ)，若指物，它還可以同 of which互換)。e.g They rushed over to help the man whose car had broken

35、down.那人車壞了, 大家者|跑過(guò)去幫，忙。Please pass me the book whose (of which) cover is green. 請(qǐng)遞給我那本綠皮的書。3) which, that它們所代替的先行詞是事物的名詞或代詞，在從句中可作主語(yǔ)、賓語(yǔ)等，例如：A prosperitywhich / that had never been seen before appears in the countryside. 農(nóng)村出現(xiàn)了前所未有的繁榮。 (which / that 在句中作賓語(yǔ))The package (which / that) you are carrying i

36、s about to come unwrapped. 你拿的包快散了。(which / that 在句中作賓語(yǔ))2 .關(guān)系副詞引導(dǎo)的定語(yǔ)從句關(guān)系副詞可代替的先行詞是時(shí)間、地點(diǎn)或理由的名詞，在從句中作狀語(yǔ)。1)when, where, why關(guān)系副詞when, where, why的含義相當(dāng)于"介詞+ which"結(jié)構(gòu)，因此常常和"介詞+ which 結(jié)構(gòu)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時(shí)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?這就是他拒絕我們幫助他的理由嗎？2 ) that代替關(guān)系副詞that可以用于表示時(shí)間、地點(diǎn)、方式、理由的名詞后取代 when, where, why和"介詞+ which"引導(dǎo)的定語(yǔ)從 句，在口語(yǔ)中that常被省略.e.g His father died the year (that / when / in which) he was born. 他父親在他出生 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他四十年前居住過(guò)的地方。3 .判斷關(guān)系代詞與關(guān)系副詞方法一：用關(guān)系代詞，還是關(guān)系副詞完全取決于從句中的謂語(yǔ)動(dòng)詞。及物動(dòng)詞后面無(wú)賓語(yǔ)，就必須要求用 關(guān)系代詞；而不及物動(dòng)詞則要求用關(guān)系副詞。例如：This is the mountain village where I stayed last year.I'll never forget the days when I worked together with you.判斷改錯(cuò)（注：先顯示題，再顯

39、示答案，橫線；用不同的顏色表示出。）（錯(cuò)） This is the mountain village where I visited last year.（錯(cuò)） I will never forget the days when I spent in the countryside.（對(duì)） This is the mountain village （which） I visited last year.（對(duì)） I'll never forget the days （which） I spent in the countryside.習(xí)慣上總把表地點(diǎn)或時(shí)間的名詞與關(guān)系副詞where, w

40、hen聯(lián)系在一起。此兩題錯(cuò)在關(guān)系詞的誤用上。方法二：準(zhǔn)確判斷先行詞在定語(yǔ)從句中的成分（主、謂、賓、定、狀），也能正確選擇出關(guān)系代詞/關(guān)系副詞。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 變?yōu)榭隙ň洌篢his museum is you visited a few

41、days ago.例 2 變?yōu)榭隙ň洌篢his is the museum the exhibition was held.在句1中，所缺部分為賓語(yǔ)，而 where, that, on which都不能起到賓語(yǔ)的作用，只有 the one既做了主句 的表語(yǔ)，又可做從句的賓語(yǔ)，可以省略關(guān)系代詞，所以應(yīng)選 D。而句2中，主、謂、賓俱全，從句部分為句子的狀語(yǔ)表地點(diǎn)，既可用副詞where,又因in the museum詞組，可用介詞in + which引導(dǎo)地點(diǎn)狀語(yǔ)。而此題中，介詞on用的不對(duì)，所以選 A。關(guān)系詞的選擇依據(jù)在從句中所做的成分，先行詞在從句中做主、定、賓語(yǔ)時(shí)，選擇關(guān)系代詞（who, who

42、m,that, which, whose）；先行詞在從句中做狀語(yǔ)時(shí)， 應(yīng)選擇關(guān)系副詞 （where地點(diǎn)狀語(yǔ)，when時(shí)間狀語(yǔ)，why 原因狀語(yǔ)）。4 .限制性和非限制性定語(yǔ)從句1）定語(yǔ)從句有限制性和非限制性兩種。限制性定語(yǔ)從句是先行詞不可缺少的部分，去掉它主句意思往往不 明確；非限制性定語(yǔ)從句是先行詞的附加說(shuō)明，去掉了也不會(huì)影響主句的意思，它與主句之間通常用逗號(hào) 分開。e.g This is the house which we bought last month.這是我們上個(gè)月買的那幢房子。（限制性）The house, which we bought last month, is very

43、 nice.這幢房子很漂亮,是我們上個(gè)月買 （非限制性）2）非限定性定語(yǔ)從句不能用that引導(dǎo)，一般用引導(dǎo)詞 which / as或who （指人），非限定性定語(yǔ)從句既可以修飾主句的部分內(nèi)容，也可彳飾主句的全部?jī)?nèi)容。as引導(dǎo)的非限定性定語(yǔ)從句既可以放在主句之前，也可以放在主句之后，但 which或who引導(dǎo)的非限定性定語(yǔ)從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非限定性定語(yǔ)從句由as, which引導(dǎo)的非限定性定語(yǔ)從句，as和which可代整個(gè)主句，相當(dāng)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.典型例題1) Alice received an invitation from her boss,came as a surprise.A. it B. that C. which D. he答案C.此為非限定性從句，不能用that修飾，而用which., it和he都使后句成為句子，兩個(gè)獨(dú)立的句子不能單以逗號(hào)連接。況且選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，用于非限定性定語(yǔ)從句，而what不可。That不能用于非限定性定語(yǔ)從句，it不為連詞，使由逗號(hào)連接的兩個(gè)句子并在一起在英語(yǔ)語(yǔ)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在引導(dǎo)非限制性定語(yǔ)從句時(shí)，這兩個(gè)關(guān)系代詞都指主句所表達(dá)的整個(gè)意思，且在定語(yǔ)從句中都可以作主語(yǔ)和賓語(yǔ)。但不同之處主要有兩點(diǎn)：(1)as引導(dǎo)的定語(yǔ)從句可置于句首，而 which不可。(2)as代

47、表前面的整個(gè)主句并在從句中作主語(yǔ)時(shí)，從句中的謂語(yǔ)必須是系動(dòng)詞；若為行為動(dòng)詞，則從句中的關(guān)系代詞只能用which. o在本題中，prevent由于是行為動(dòng)詞，所以正確選項(xiàng)應(yīng)為B。As的用法例1. the same as； such- as中的as是一種固定結(jié)構(gòu)，和一樣。I have got into the same trouble as he (has).例2. as可引導(dǎo)非限制性從句，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是關(guān)系代詞。例1中的as作know的賓語(yǔ)；例2中，它充當(dāng)從句的主語(yǔ)，謂語(yǔ)動(dòng)詞know要用被動(dòng)式。6.介詞+關(guān)系詞1）介詞后面的關(guān)系詞不能省略。2） that前不能有介詞。3）某些在從句中充當(dāng)時(shí)間，地點(diǎn)或原因狀語(yǔ)的"介詞+關(guān)系詞"結(jié)構(gòu)可以同關(guān)系副詞 when和where互換。 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.關(guān)系代詞that的用法1）不用that的情況a）在引導(dǎo)非限定性定語(yǔ)從句時(shí)。（錯(cuò)） The tree, that is four hundred years old, is very famous here.b）介詞后不能用。We depend on the land from that we get our food.（錯(cuò)）改為： 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作為定語(yǔ)從句的關(guān)系代詞的情況當(dāng)先行詞是不定代詞時(shí) ，如:all, little, much, none, one, everyone, something, anything, everything, nothing 等。e.g That ' s all that I could do at that time.就是我那是所能為你做的全部。當(dāng)先行詞被 the only, the very, the same, little, few, no,等修飾時(shí)。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。當(dāng)先行詞被序數(shù)詞或形容詞最高級(jí)修飾時(shí)。e.g He was the first person that passed the examination他是第個(gè)通過(guò)這個(gè)考試的人。This is the best way that can solve the problem.這是解決那個(gè)問(wèn)題的最好辦法。被修飾詞為數(shù)詞時(shí)，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. 昨天我媽媽買了 兩只狗?，F(xiàn)在你能看見(jiàn)它們?cè)谀沁呁妗Ｖ骶涫莟here be結(jié)構(gòu)，修飾其主語(yǔ)的定語(yǔ)從句thate.g There is a book on the desk that belongs to Jack桌上那本書是杰克的。主句是以which或who開頭的特殊疑問(wèn)句時(shí)，關(guān)系代詞只能用that。e.g Who is the girl that is talking with Mr. Brown ?如果出現(xiàn)兩個(gè)或兩個(gè)以上的先行詞，并同時(shí)兼指人和物時(shí)，關(guān)系代詞用that。e.g We are talking about the people and countries that we

53、 have visited.如果兩個(gè)從句，其中一個(gè)關(guān)系代詞已用which,另一個(gè)關(guān)系代詞應(yīng)用that,以避免重復(fù)。e.g He built up a factory which produced things that had never been seen before.他辦了一家工廠，生產(chǎn)過(guò)去從未見(jiàn)到的東西。三.狀語(yǔ)從句副詞性從句(狀語(yǔ)從句)狀語(yǔ)從句主要用來(lái)修飾主句或主句的謂語(yǔ)。一般可分為十大類，分別表示時(shí)間、地點(diǎn)、原因、目的、結(jié)果、 條件、讓步、比較 、方式和程度。1 .時(shí)間狀語(yǔ)從句(1)常用弓I導(dǎo)詞： when, as, while, as soon as, before, after

54、, since , till, ( until )特殊弓I導(dǎo)詞： 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 (果園)the moment they saw the guard.when, while, as引導(dǎo)時(shí)間狀語(yǔ)從句時(shí)的異同when引導(dǎo)的時(shí)間狀語(yǔ)從句中的謂語(yǔ)動(dòng)詞既可以是延續(xù)性動(dòng)詞，也可以是短暫性動(dòng)詞；從句的動(dòng)作可以和主句的動(dòng)作同時(shí)發(fā)生，也可以先于主句的動(dòng)作發(fā)生，此時(shí)相當(dāng)于aftero當(dāng)when從句謂語(yǔ)動(dòng)詞是延續(xù)性動(dòng)詞時(shí)，可與while互換。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從句置于主句后面，同時(shí)從句中謂語(yǔ)動(dòng)詞又是短暫性動(dòng)詞時(shí)，常表示此時(shí)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引導(dǎo)的動(dòng)作必須是持續(xù)性的，強(qiáng)調(diào)主句和從句動(dòng)作的同時(shí)發(fā)生，有時(shí)側(cè)

57、重主句和從句動(dòng)作的對(duì)比。He took a bath while I was preparing dinner.as?？膳cwhen, while通用，但它較強(qiáng)調(diào)主句和從句動(dòng)作的同時(shí)發(fā)生，常譯作 邊邊”也可用來(lái)說(shuō)明 兩種正在發(fā)展和變化的情況，此時(shí)常譯作 隨著”。e.g He sang happily as he walked along the path.The day gets longer and longer as summer comes.until, till引導(dǎo)的時(shí)間狀語(yǔ)從句主句謂語(yǔ)動(dòng)詞為延續(xù)性動(dòng)詞時(shí)，主句和從句都用肯定句式，意為直到"，表示主句動(dòng)作一直延續(xù)到until/till從句表示的時(shí)間才終止；主句謂語(yǔ)動(dòng)詞為短暫性動(dòng)詞時(shí)，主句用否定式，從句用肯定式，意思是-直到才”，表示主句動(dòng)作到until/till從句表示的時(shí)間才開始。e.g He worked until/till it was dark.He didn ' t work until/till it was dark.until和till意義相同，通?？蓳Q用，但在強(qiáng)調(diào)結(jié)構(gòu)、倒裝句或句首，一般用