英語(yǔ)三大從句

1、復(fù)合句【語(yǔ)法要點(diǎn)】復(fù)合句是由一個(gè)主句加一個(gè)或幾個(gè)從句所構(gòu)成的句子。從句只用作句子的一個(gè)成分，不能獨(dú)立。根據(jù)從句在句子中的作用，可分為名詞性從句、定語(yǔ)從句和狀語(yǔ)從句三類(lèi)。（一）名詞性從句名詞性從句包括主語(yǔ)從句、表語(yǔ)從句、賓語(yǔ)從句、同位語(yǔ)從句。其關(guān)聯(lián)詞有連接詞that、if、whether；疑問(wèn)代詞who、what、which和疑問(wèn)副詞when、where、how、why等。1.名詞性從句句法結(jié)構(gòu)：從屬連詞thatwhether主語(yǔ)從句That he will come is certain.（that不可?。￤hether she is coming or not doesnt matter t

2、oo much.（不能用if）賓語(yǔ)從句I think（that）he will be all right in a few days.I went in and asked if（=whether）they had a cheap suit.I wonder whether（不能用if）it is true or not.表語(yǔ)從句The fact is（that）I have never been there.The question is whether（不能用if）it is worth doing.同位語(yǔ)從句The fact that she had not said anything

3、surprised all of us.They asked me the question whether the work was worth doing.連接代詞thatwhowhomwhosewhich主語(yǔ)從句Who will help him is not known.What he said is very important.Which side will win is not clear.賓語(yǔ)從句（1）作及物動(dòng)詞的賓語(yǔ)。例如：I really dont know what he is doing.Do you know who/whom they are waiting for

4、?He asked whose dictionary it was.He cant tell which method they will use for the experiment.（2）作介詞的賓語(yǔ)。例如：Pay attention to what the teacher said.I wondered to whom he had given the letter.表語(yǔ)從句That is what he is worried about.The question is who will come here.The question is which team will win the

5、match.連接副詞wherewhenwhyhow主語(yǔ)從句Where she has gone is not known yet.When they will start is not known yet.Why he did it wasnt quite clear.How he became a great scientist is known to us all. 賓語(yǔ)從句I dont know where we are going to have the meeting.Please tell me when we shall discuss our work plan.Do you

6、know why he said that?Will you tell me how I can get to the railway station?表語(yǔ)從句That is where he was born.This is why he is late.This is how he did it.The question is when he will be back.同位語(yǔ)從句I have no idea when he will come back.You have no idea how worried I was.The problem is where we can get so

7、 much money. 2.名詞性從句的其它用法：1）if不能引導(dǎo)表語(yǔ)從句。連接代詞who、what、whose、which不能引導(dǎo)同位語(yǔ)從句。2）有時(shí)as、as if/though、because也可以引導(dǎo)表語(yǔ)從句，能跟表語(yǔ)從句的謂語(yǔ)動(dòng)詞一般為系動(dòng)詞be、seem、look等。例如：Things are not always as they seem to be. 事情并不總是像表面上看來(lái)的那樣。It looks as if it were going to rain. It is because you eat too much. 3）介詞賓語(yǔ)不可以用which來(lái)引導(dǎo)，而要用what來(lái)引

8、導(dǎo)。例如：We can learn what we did not know. He will talk to us about what he saw in the U.S.4）連詞that引導(dǎo)的名詞性從句除能用在except、but、in后之外很少作介詞的賓語(yǔ)，。其它一些介詞的賓語(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)。例如：He is a good student except that he is careless.You may depend on it that they will support you.5）若主句謂語(yǔ)動(dòng)詞是及物動(dòng)詞make、find、think

9、、see、hear等，則把賓語(yǔ)從句置于賓語(yǔ)補(bǔ)足語(yǔ)之后，用it作形式賓語(yǔ)。例如：We find it necessary that we practise spoken-English every day.6）某些作表語(yǔ)的形容詞或過(guò)去分詞后常接賓語(yǔ)從句，如sure、happy、glad、certain、pleased、afraid、surprised、satisfied等，連詞that可省略，有的語(yǔ)法書(shū)稱(chēng)之為狀語(yǔ)從句。例如：I am sure that he will succeed.I am afraid you dont understand what I said.Mother was v

10、ery pleased her daughter had passed the exams.7）連接代詞whoever、whatever、whichever也可引導(dǎo)賓語(yǔ)從句。例如：I will show you whatever you want to see.You may choose whoever you like. I will take whichever fits the sockets.（插座）8）同位語(yǔ)從句一般跟在某些表示抽象概念的名詞后面，用以說(shuō)明名詞所表示的具體內(nèi)容。常跟同位語(yǔ)從句的名詞主要有：idea、news、fact、promise、answer、belief、co

11、ndition、doubt、fear、hope、order、problem、proof、question、reply、report、suggestion、thought、 truth等。由連詞that引導(dǎo)同位語(yǔ)從句既無(wú)語(yǔ)法功能，也無(wú)詞匯意義，只是引導(dǎo)詞；由連詞whether引導(dǎo)同位語(yǔ)從句無(wú)語(yǔ)法功能，但有詞匯意義“是否”；由連詞when、where、how引導(dǎo)同位語(yǔ)從句在句中分別作作時(shí)間、地點(diǎn)和方式狀語(yǔ)。注意關(guān)聯(lián)詞只能用whether不能用if表示“是否”的情況如下：A)在表語(yǔ)從句和同位語(yǔ)從句中。例如：The question is whether the film is worth seein

12、g.The news whether our team has won the match is unknown.B)在主語(yǔ)從句中，只有it作形式主語(yǔ)時(shí)whether和if均可。否則，也只能用whether。例如：Whether we shall attend the meeting hasnt been decided yet.It hasnt been decided whether/if we shall attend the meeting.C)在介詞之后（介詞往往可以省略）。例如：It all depends (on) whether they will support us.D)后

13、面直接跟動(dòng)詞不定式時(shí)。例如：He doesnt know whether to stay or not.E)與or not連用時(shí)。例如：We didnt know whether or not she was ready. 關(guān)聯(lián)詞if、whether均可使用的情況如下：A)引導(dǎo)賓語(yǔ)從句，但當(dāng)賓語(yǔ)從句是否定句時(shí)，一般用if引導(dǎo)。例如：I wonder if/whether the news is true or not. I dont care if it doesnt rain.B)在“be+形容詞”之后。例如：He was not sure whether/if it is right or

14、 wrong.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whether。試比較：Please let me know if you want to go. Please let me know whether you want to go.（if從句既可理解為賓語(yǔ)從句，也可理解為條件狀語(yǔ)從句）doubt作“懷疑”解接賓語(yǔ)從句時(shí)，主句為肯定句用whether或if，主句為否定句或疑問(wèn)句用that。10）it作形式主語(yǔ)that所引導(dǎo)的主語(yǔ)從句常由代詞it作形式主語(yǔ)。且wh-系列引導(dǎo)詞引導(dǎo)的從句均可。例如： It makes everyone happy that the girl is

15、still alive. It doesnt matter too much whether hes coming or not.It is still open to question who is to head the group. 誰(shuí)領(lǐng)導(dǎo)這個(gè)小組還沒(méi)定下來(lái)。 常以it作形式主語(yǔ)的句型有：It +be+形容詞(obvious、true、natural、surprising、good、wonderful、funny、possible、likely、certain、probable)+that從句It +be+名詞詞組(no wonder、an honour、a good thing、a p

16、ity、no surprise)+that從句It +be+過(guò)去分詞(said、reported、thought、expected、decided、announced、arranged)+that從句It +seem、happen等不及物動(dòng)詞及短語(yǔ)+that從句It +doesnt matter(makes no difference, etc)+連接代詞或連接副詞引導(dǎo)的主語(yǔ)從句當(dāng)that引導(dǎo)的主語(yǔ)從句出現(xiàn)在疑問(wèn)句中時(shí)，也要以it作形式主語(yǔ)，而把主語(yǔ)從句后置。例如：Is it true that the scientist will give us a lecture next week?（二

17、）定語(yǔ)從句在復(fù)合句中修飾名詞或代詞的從句叫定語(yǔ)從句。被修飾的名詞或代詞叫先行詞。引導(dǎo)定語(yǔ)從句的關(guān)系代詞有who、whom、whose、which、that等和關(guān)系副詞where、when、why等。關(guān)系代詞和關(guān)系副詞在定語(yǔ)從句中擔(dān)任句子成分。而引導(dǎo)引導(dǎo)非限定性定語(yǔ)從句的關(guān)系代詞有who、whom、whose、which、of which等，這些關(guān)系代詞都不能省略，通常不用關(guān)系代詞that。例如：I have two sisters, who are both students.關(guān)系詞whowhichthatwhosewherewhen指代人物、地點(diǎn)等動(dòng)物、物、地點(diǎn)等所有者地點(diǎn)時(shí)間例如：This

18、 is the man who helped me. They have a dog whose barking drives me mad.I know the reason why he came late. This is the place where we lived for 5 years.I will never forger the day when I met Mr. Liu. The doctor whom you are looking for is in the room.注意先行詞表示地點(diǎn)時(shí)，有時(shí)用where，有時(shí)用that引導(dǎo)定語(yǔ)從句。這時(shí)要根據(jù)從句的謂語(yǔ)動(dòng)詞是及物

19、的還是不及物的，是及物的就用that(which),否則就用where。例如;This is the house where he lived last year.This is the house that (which) he visited last year.關(guān)系代詞which、who或that在限定性定語(yǔ)從句中作賓語(yǔ)時(shí)可省略。例如：Amsterdam is the place we like most.They are looking for a person (who) they can rely on.在定語(yǔ)從句中，若先行詞指人，其關(guān)系代詞可用who、whom，也可用that。例

20、如：The girl who/that is speaking at the meeting is our monitor.在下列情況下多用或須用who。關(guān)系代詞在從句中作主語(yǔ)時(shí)。例如： The doctor who treated me was very experienced. 給我治病的醫(yī)生是很有經(jīng)驗(yàn)的。先行詞為all、anyone、one、ones、those、people等時(shí)。例如：All who heard the news were excited. 所有聽(tīng)到這消息的人都感到興奮。Those who want to go please sign their names here.

21、 想去的人請(qǐng)?jiān)谶@里簽名。在非限制性定語(yǔ)從句中。例如：Toms father, who is over sixty, still works hard. 在被分隔的定語(yǔ)從句中。例如：A new teacher will come tomorrow who will teach you German. 在以there be開(kāi)頭的句子中。例如：There is a strange who wants to see you.一個(gè)句子中帶有兩個(gè)定語(yǔ)從句，其中一個(gè)關(guān)系代詞是that，另一個(gè)須用who。例如：The student who was praised at the meeting is the

22、monitor that is very modest and studied very hard. 在會(huì)上受到表?yè)P(yáng)的學(xué)生是班長(zhǎng)，他謙虛好學(xué)。whose引導(dǎo)定語(yǔ)從句應(yīng)注意以下幾點(diǎn)：whose引導(dǎo)定語(yǔ)從句，其先行詞不僅可以指人，還可以指物。例如：It was a meeting whose importance I didnt realize at the time. whose在定語(yǔ)從句中可與它修飾的名詞一起作介詞賓語(yǔ)，與介詞放在先行詞與從句之間。例如：The boss in whose department Mr. King worked had heard about the accide

23、nt.Tom, on whose bike I went to school is a friend of mine. whose的先行詞指物時(shí)，可用of which代替whose，但詞序不同。例如：The novel whose title is Red and Black is very interesting. (=the title of which) 2.介詞+關(guān)系代詞中介詞的選擇介詞的選擇要看三方面：一要看和先行詞是否搭配；二要看和定語(yǔ)從句中謂語(yǔ)動(dòng)詞是否搭配；三要根據(jù)定語(yǔ)從句的意義來(lái)選擇。例如：This is the car by which I went to Jinan. (b

24、y car)Tomorrow we will have a meeting at which we will discuss some problems. (at the meeting)The student to whom I spoke has gone home. (speak to) 3.which和that引導(dǎo)定語(yǔ)從句的區(qū)別which在從句中作主語(yǔ)或謂語(yǔ)動(dòng)詞及介詞的賓語(yǔ)。that在定語(yǔ)從句中可以指人或物，在從句中作主語(yǔ)或謂語(yǔ)動(dòng)詞的賓語(yǔ)。但不能放在介詞后面作介詞賓語(yǔ)。例如： This is the book which you want.The building which stan

25、ds near the river is our school.The room in which there is a machine is workshop. The letter that I received was from my father.（1）只能用which不能用that的情況引導(dǎo)非限制性定語(yǔ)從句。關(guān)系詞在從句中作介詞賓語(yǔ)且位于介詞之后。例如：This is the house in which I once lived.（2）用that的情況先行詞既有人又有物時(shí)先行詞為不定代詞修飾時(shí)（all、few、little、much、something、nothing、anythi

26、ng等）先行詞前有形容詞最高級(jí)或序數(shù)詞所修飾時(shí)先行詞被all、any、every、few、little、no、some等修飾或被the only、the very、the same、the last、just等修飾時(shí)關(guān)系代詞在從句中作表語(yǔ)時(shí)there be結(jié)構(gòu) 例如： All that we have to do is to practise every day.The first lesson that I learned will never be forgotten.I have read all the books (that) you gave me.He is the only p

27、erson that I want to talk to.They talked of things and persons that they remembered in the school.The village is no longer the one that used to be. 注意whom、which作介詞賓語(yǔ)時(shí)，介詞一般可放在which之前，也可放在原來(lái)的位置上，在有介詞的動(dòng)詞固定詞組中，介詞只能放在原來(lái)的位置上。例如：This is the person whom you are looking for.當(dāng)主句是以who或which開(kāi)頭的特殊疑問(wèn)句時(shí)，定語(yǔ)從句須用that

28、，以免與先行詞重復(fù)。例如：Who is the boy that was here just now? 4.as引導(dǎo)的定語(yǔ)從句1)as用作關(guān)系代詞和關(guān)系副詞引導(dǎo)限定性定語(yǔ)從句，并在從句中作定語(yǔ)、表語(yǔ)或狀語(yǔ)，構(gòu)成the sameas, suchas等結(jié)構(gòu)。例如：I like the same book as you do. (as作賓語(yǔ))I shall do it in the same way as you did. (as作狀語(yǔ))2)as引導(dǎo)非限定性定語(yǔ)從句。as在定語(yǔ)從句中作主語(yǔ)、表語(yǔ)或賓語(yǔ)，這個(gè)定語(yǔ)從句是說(shuō)明整個(gè)句子，位置可前、可中、可后，意為“正如、好像”。例如：Such stamps

29、 as you have collected are very valuable.As we all know, he studies very hard. (as作賓語(yǔ)) They remarried, as we had expected. 常用的這種類(lèi)似插入語(yǔ)的句式有as is said above, as is known to all, as it is等。注意關(guān)系代詞在從句中作主語(yǔ)時(shí)，從句的謂語(yǔ)動(dòng)詞的人稱(chēng)和數(shù)必須和先行詞保持一致。關(guān)系代詞which和as在定語(yǔ)從句中的區(qū)別是：which不能放在句首，而as則可以；在句中時(shí)，as有“正如”、“就像”之意，而which則沒(méi)有。同位語(yǔ)從句

30、與定語(yǔ)從句的區(qū)別：定語(yǔ)從句是形容詞性從句，引導(dǎo)詞是關(guān)系詞，關(guān)系詞代替先行詞的意思在定語(yǔ)從句中作成分；同位語(yǔ)從句是名詞性從句引導(dǎo)詞是連接詞，that、whether、if在句中不作任何成分，連接代詞和連接副詞本身意義在同位語(yǔ)從句中作成分。例如：A. The news that they had won the game arrived soon. （同位語(yǔ)從句）（the news和that they had won the game無(wú)邏輯關(guān)系）B. The news that you told me yesterday is true.（定語(yǔ)從句）（the news在從句中相當(dāng)于told的邏輯賓

31、語(yǔ)）（三）狀語(yǔ)從句狀語(yǔ)從句在句中作狀語(yǔ)，修飾主句中的動(dòng)詞、形容詞或副詞等。狀語(yǔ)從句放在主句之前時(shí)，常用逗號(hào)隔開(kāi)；放在主句之后，一般不用逗號(hào)。1.狀語(yǔ)從句分類(lèi)及其常用連詞：類(lèi)別常用連詞時(shí)間狀語(yǔ)從句when、while、as、before、after、since、until（till）、once、as soon as等地點(diǎn)狀語(yǔ)從句where、wherever等原因狀語(yǔ)從句because、since、as、now that等目的狀語(yǔ)從句so、so that、in order that、in case、lest、for fear that等結(jié)果狀語(yǔ)從句so that、sothat、suchthat等

32、條件狀語(yǔ)從句if、unless、as/so long as、on condition that、in case、once、provide that等讓步狀語(yǔ)從句though、although、even if/though、as、when、while、no matter等比較狀語(yǔ)從句asas、not soas、than、the morethe more等方式狀語(yǔ)從句(just)as、as if/though等 2.引導(dǎo)狀語(yǔ)從句的常見(jiàn)連詞用法when, while和as（1）when引導(dǎo)的時(shí)間從句中的動(dòng)詞既可以是延續(xù)性動(dòng)詞，也可以是非延續(xù)性動(dòng)詞。（2）while引導(dǎo)的時(shí)間從句中的動(dòng)詞通常是延續(xù)性動(dòng)

33、詞。（3）as引導(dǎo)的時(shí)間從句中的動(dòng)詞是延續(xù)性動(dòng)詞時(shí)，則側(cè)重表示從句的動(dòng)作和主句的動(dòng)作同時(shí)發(fā)生，意為：一邊一邊。例如：I was fat when I was a child.When the film ended, people rushed out of the hall.He took a bath while I was preparing dinner.He sang songs as he was taking a bath.注意1）when可以作并列連詞，用以連接并列句，意為：這時(shí)突然。常構(gòu)成下列句式：was/were doingwhen 正在突然。例如：I was working

34、 in the garden when it began to rain.be about to dowhen 正要突然。例如：We were about to go out when the rain poured down.be on the point of doingwhen 正要突然。例如：I was on the point of going out when the telephone rang.2）when還可引導(dǎo)原因狀語(yǔ)從句，意為：既然，考慮到，相當(dāng)于since，considering that。例如：How can they learn anything when they

35、 spend all their spare time watching TV?3）while也可作并列連詞，意為“然而”。例如：Mum was sewing while dad was watching TV.4）while還可引導(dǎo)讓步狀語(yǔ)從句，意為“盡管”。例如：While I admit his good points, I can see his shortcomings.till與until（1）till與until意思相同，只是till一般不放在句首。、（2）主句的謂語(yǔ)動(dòng)詞如果是延續(xù)性動(dòng)詞，主句要用肯定式，意為：直到為止。（3）主句的謂語(yǔ)動(dòng)詞如果是非延續(xù)性動(dòng)詞，主句要用否定式，意為

36、：直到才。（4）在“It is not untilthat”（直到才）句型中，要用until不用till。（5）not until置于句首時(shí)，句子需要部分倒裝。例如：I will stay here until/till the rain stops. He didnt go to bed until/till I came back.It was not until I came back that he went to bed. Not until I came back did he go to bed.before與since （1）before引導(dǎo)的從句中一般不用否定式謂語(yǔ)，常用句型

37、有：It was/will be+時(shí)間段+before。It was not/wont be+時(shí)間段+before。例如：It was long before I came. It was not long before he told me about this affair.（2）since后的動(dòng)詞不同，起算的時(shí)間也不同。since+非延續(xù)性動(dòng)詞的過(guò)去式，從該動(dòng)作發(fā)生時(shí)算起since+延續(xù)性動(dòng)詞的過(guò)去式，從該動(dòng)作結(jié)束時(shí)算起例如：It is two years since he joined the army. It is two years since he was a soldier.b

38、ecause、now that/since、as與for區(qū)別項(xiàng) 目位置內(nèi)涵語(yǔ)氣能否回答why能否被強(qiáng)調(diào)because主句前或后直接因果關(guān)系強(qiáng)能能as主句前或后雙方都知道的原因弱不能不能since/now that既然主句前for并列連詞，句中間接的、推斷的原因最弱不能不能例如：As it is raining, we shall not go to the park.Now that everybody is here, lets begin our meeting.He must be ill, for he is absent today. It is because he was ill

39、 that he didnt go with us.although、though與as1）三者都可以引導(dǎo)讓步狀語(yǔ)從句，although引導(dǎo)讓步狀語(yǔ)從句時(shí)用正常語(yǔ)序，though可用正常語(yǔ)序也可用倒裝語(yǔ)序。as必須用倒裝語(yǔ)序，從句中的表語(yǔ)、狀語(yǔ)或動(dòng)詞原形置于句首；若表語(yǔ)是名詞，前置要省略冠詞。例如：He is unhappy, though/although he has a lot of money.Difficult as/though the task was, they managed to finish it in time.Child as/though he is, he kno

40、ws a lot.2）though和although在引導(dǎo)讓步狀語(yǔ)從句時(shí)不可與but連用，但可以和yet連用。例如：Although/Though it was raining hard, yet they went on playing football.3）though還可作副詞，意為“可是，然而”。置于句末。例如：He said he would come; he didnt, though.4）even though/if引導(dǎo)的讓步從句中視具體情況可用陳述語(yǔ)氣或虛擬語(yǔ)氣。例如：Even though/if it is raining, well go there.（陳述語(yǔ)氣） Even

41、 if I were busy, I would go.（虛擬語(yǔ)氣）whetheror （不管還是）以及疑問(wèn)詞+ever與no matter+疑問(wèn)詞（不管/無(wú)論），也可引導(dǎo)讓步狀語(yǔ)從句。例如：Whether you believe or not, it is true.Whatever（=no matter what）you say, he wont believe you.Whoever you are（=no matter who you are）, you must obey the rules.unless與if not很多情況下，兩者可換用。例如：You will be late u

42、nless you hurry/if you dont hurry.在下列結(jié)構(gòu)中，unless與if not不可相互替代。（1）當(dāng)if not引導(dǎo)非真實(shí)條件句時(shí)一般不可用unless。例如：If Henry hadnt been tended carefully, he couldnt have lived so long.（2）unless表示除外的唯一條件，因此常不用and連接兩個(gè)unless從句，而if not不受此限制。例如：If you dont eat fresh vegetable and you dont have enough exercise, you wont keep

43、it.（3）unless從句中可用否定詞，if not從句中不可再用一個(gè)否定詞I will go unless no one else does.（4）在if not從句中，常用any、yet、either、at all等非肯定詞，而在unless從句中常用some、already、still、too等肯定詞。例如：I will be angry if you havent spoken to her yet.I will be angry unless you have already spoken to her. as/as if/as thoughas/as if/as though都可

44、引導(dǎo)方式狀語(yǔ)從句，其中as if或as though引導(dǎo)的從句一般用虛擬語(yǔ)氣，但如果從句中所敘述的情況很可能實(shí)現(xiàn)，也可用陳述語(yǔ)氣。例如：Do as you are told to, or you will be fired. The old lady treats the boy as if he were her own son.in order that與so that二者都可引導(dǎo)目的狀語(yǔ)從句，in order that引導(dǎo)的目的狀語(yǔ)從句可置于句首，但so that在引導(dǎo)目的狀語(yǔ)從句時(shí)不可置于句首。例如：He got up early so that/in order that he could catch the first bus.In order that he could catch the first bus, he got up early.除此之外，for fear that、in case與lest也可引導(dǎo)目的狀語(yǔ)從句，從句謂語(yǔ)動(dòng)詞要用（should）+動(dòng)詞原形。sothat與suchthat 二者都可引導(dǎo)結(jié)果狀語(yǔ)從句，注意其結(jié)構(gòu)形式的區(qū)別：so+形容詞/副詞+that從句so+形容詞+a/an+可數(shù)名詞單數(shù)+that從句so+many/much/few/li