主语从句详解

1、主语从句详解一、概述在句子中起名词作用的各种从句统称为名词性从句. 根据它们在句中的语法作用,这类从句又可分为主语从句、同位语从句、表语从句和宾语从句.二、主语从句主要有四类（1） 由连词 that引导的主语从句: 引导词 that例如： That you will win the medal seems unlikely.That you are so indifferent bothers me.That she survived the accident is a miracle.无含义/ 在句中不做成分/ 不可以省.（2） 用连词whether引导的主语从句: whether有含义 (

2、 是否 )/ 在句中不做成分/ 不可以省.注意：引导主语从句,不能用 if,只能用 whether.例如： Whether we willholda partyinthe open airWhether she is ing or not doesnt matter too much.tomorrow depends on the weather.（3） 用连接代词引导的主语从句在由连接代词who, whose, whom, which,what, whoever,whomever, whichever,whatever引导的名词性从句中,其连接代词在句中起名词性作用,担当一定成分 .例如：

3、What you need is more practice. What I want to know is this.Whatever we do is to serve the people.注： whatever / whoever的功用whatever, whoever在主语从句中不含疑问意义. 它引导主语从句,并在从句中作主语、宾语、表语等 .whatever = anything that; whoever = anyone who.让步状语从句的区别.Whoever breaks the law should be punished.要注意和（主语从句）whatever, who

4、ever引导的（ Anyone who breaks the law should be punished.）Whoever breaks the law, he should be punished.（让步状语从句）（ No matter who breaks the law, he should be punished.）（ 4）用连接副词 when, where, why, how引导名词性从句 ( 其连接副词有含义 , 在句中作状语 .)例如 :Where we should leave it is a problem.When they will e hasn t been made

5、 pubic.三、注意点 : it构成的主语从句（ 1）由连词 that 引导的主语从句 , 在多数情况下放到句子的后面 , 而用代词 it 作形式主语 .例如： That light travels in straight lines is known to all.=It is known to all that light travels in straight lines.When the plane is to take off has not been announced .= It has not been announced when the plane is to take

6、off.( 但当 what 引导的主语从句表示“ 的东西”时,一般不用错:It is a book what he wants.对:What he wants is a book.it作形式主语.)另外 ,需要注意的是, it作形式主语代替主语从句时,要注意和as 引导的定语从句的区别.试比较：It was reported that the US was under the terrorist attack.As was reported, the US was under the terrorist attack.（2）常见用it作形式主语的复合句结构A. It is +名词 +从句It

7、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 mon 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.It is mon knowledge that the whale is not a fish.B. It is +形容词 +从句It is necessary that有必要 It is

8、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 doubtful whether she will be able to e.It was really astonishing tha

9、t he refused to talk to you.It is essential that he should be here by the weekend.It seems obvious that we cannot go on like this.It is necessary that you（ should ） master the puter.It is important that a student learn English well.It is likely that a hurricane will arrive soon.需要注意的是,这类主语从句中,谓语动词很多

10、为“ （should ）动词原形”,即要用虚拟语气 .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 thou

11、ght that he is the best player.It is estimated that the vase is 2000 years old.Itis used to be thoughtthata new starmust be due to a collisionbetween two stars.It has not been made clear when the new road is to be opened to traffic.It is said that he was killed in the earthquake.D. Itseems（ happened

12、 / appears / doesn t matter / makes no difference / occurred ） thatIt seems that they will win the game.It makes no difference whether he will attend the meeting or not.It does not matter if I missed my train.It happened that I saw him yesterday.主从练习1. _asmuchasone-fifthofalltimberharvestedisnotused

13、.A.TheestimateB.TheestimatedC.TheyareestimatedD.Itisestimatedthat2._some mammals cametoliveintheseaisnotknown.A.WhichB.SinceC.AlthoughD.How3._wehaveachievedisattributedtotheguidanceofourparents.A.WhoeverB.WhateverC.HoweverD.That4._wealthydoesnotnecessarilymeanthatamanisgreedy.A.ForthereasonthatheisB

14、.Just becauseheisC.ThereasonofbeingD.Thatheis5.Although_happenedinthisdevelopedcountrysoundslikesciencefiction,itcouldoccur elsewhereintheworld.A.whichB.whatC.howD. it6._shehadforgottentotakehernotebook.A.ThatoccurredtoherB.SheoccurredthatC.ToherthatoccurredD.Itoccurredtoherthat7.IamsurethatA.which_

15、shesaidiswrong.B.allC.thisD. what8.WelostourwaythatitwasgettingA.thatintheforest,and_dark.B.whichmademattersC.itworsewasD. What9._ornotisstilluncertain.A. HesingC.ThatingB.IfheisingD.Whetherhe sing10.It s_he llA.doubtwhetherD.doubtfulwhetherbeB.abledoubtfultoe.C.doubtit11._heisatworkintheheartoftheb

16、igcityorat homeinthequietsuburb,Dick slifeistiedtomachines.A.WhetherB.TillC.IfD.Unless12._hesawbothsurprisedandfrightenedhim.A.ThatB.WhenC.WhatD.Which13._iswarmsunshine.A.Whatdoweallneed.B.WhatallweneedC.WhatweneedD.Whatweallneed14._isapitythatheshouldfeelsoupset.A.WhatB.ThatC.HeD.It15._aspoonfulofs

17、oilcantellussomuchaboutthestructureandearlyhistoryofthemoon.A.RemarkableB.QuiteremarkablyC.act16.Itisremarkablethat_younominateA.WhothatwillB.beelected.WhomD.ItisremarkableC.WhomeverfD. That s17._ A.book Whatyouborrow B.must Whichbereturnedwithinaweek.C.WhicheverD.That s18._ A.ofusgetsWhohomeB.first

18、Whichstartscooking.C.WhicheverD. Anyone1._ makes mistakes must correct them.A. What B. That C. Whoever D. Whatever2. It worried her a bit _ her hair was turning grey. A. while B. that C. if D. for3.When and why he came here _ yet.A. is not known B. are not knownC. has not known D. have not known4. _

19、 is no reason for dismissing her. A. Because she was a few minutes lateB. Owing to a few minutes lateC. The fact that she was a few minutes late D. Being a few minutes late5. _ Tom liked to eat was different from _.A. That that you had expected B. What that you had expected C. That what you had expe

20、cted D. What what you had expected6._ we go swimming every day _ us a lot of good.A. If.do B. That.do C. If.does D. That.does7.It _ Bob drives badly.A. thinks that B. is thought what C. thought that D. is thought that 8.It's uncertain _ the experiment is worth doing. A. if B. that C. whether D.

21、how9._ the boy didn't take medicine made his mother angry.A. That B. What C. How D. Which10._ we can't get seems better than _ we have.A. What, what B. What, that C. That, that D. That, what11._ you don't like him is none of my business.A. What B. Who C. That D. Whether12._ we'll go

22、camping tomorrow depends on the weather.A. If B. Whether C. That D. Where13._is going to do the job will be decided by the Party mittee.A. That B. Why C. How D. Who14._we'll finish translating the book depends on the time.A. When B. Why C. What D. That15._he won't go there is clear to all of

23、 us.A. How B. What C. Why D. This16._the house will be built will be discussed at tomorrow's meeting.A. If B. Where C. That D. What17._you e or not is up to you.A. What B. If C. Why D. Whether18._makes mistakes must correct them.A. Who B. Anyone C. Whoever D. Anybody19._team will win the match i

24、s a matter of public concern.A. Which B. That C. If D. How20. Who is this factory _ some foreign friends visited last Friday? A. that B. where C. which D. the one21.Is this factoryyou visited the other day?A. that B. where C. in which D. the one22._leaves the room last ought to turn off the lights.A

25、. Anyone B. The person C. Whoever D.Who表语从句1、概述用作表语的从句叫作表语从句,它位于主句中的连系动词之后. 引导表语从句的词有从属连词 that 、 whether 、as though(if) ；关系代词 who, what, which, whom, whose, whatever, whoever, whomever, whichever 等；关系副词 when, where, why, how, however, whenever,wherever 等 . 可以接表语从句的连系动词由be, look,remain,seem等 .That引导表

26、语从句时, 在口语中 , 间或可以省略 .The trouble is that we are short of money.困难是我们资金短缺 .That is why stone walls are used instead of fences around New England fields.这就是为什么在新英格兰用石头墙而不用栅栏的原因.At that time, it seemed as if I couldn't think of the right word anyhow.当时, 我似乎怎么也想不出一个恰当的字眼来.2、由从属连词 that, whether引导的表语从

27、句 .that 在引导表语从句时无词义, 而 whether 有词义 , 意为、“是否” . 这时主句的主语常常是些抽象名词 , 如 question(问题 ), trouble(麻烦 ), problem(问题 ), result(结果 ),chance( 可能性 ), suggestion(建议 ), idea( 想法 ), reason( 理由 ) 等 . 表语从句对主句主语进行说明、解释 , 使主语的内容具体化 .The trouble is (that) she has lost his money.麻烦的事是他丢了钱 .The question is whether we need

28、 more ice cream.问题是我们是否还需要一些冰淇淋.The problem was that it was too valuable for everyday use.贵重了 .What she couldn t understandwas thatfewerand fewer问题是它作为日常之用太studentsshowed interestinher lessons.我们不能理解越来越少的学生对他的课不感兴趣.3、由关系代词引导的表语从句.关系代词who, what, which, whom, whose, whatever, whoever, whomever, whiche

29、ver等引导表语从句 , 在句中作主语、宾语、表语 ,关系代词不能省略 .The question is which of us should go.问题是我们哪一个应该去 .The problem was who could do the work.问题是谁能做这项工作 .That's what he is worrying about.那就是他在担心的事 .That's what we should do.那是我们应该做的 .4、由关系副词引导的表语从句 .Go and get your coat. It's where you left it.去把雨衣拿来 . 就

30、在你原来放的地方 .I had neither a raincoat nor an umbrella. That s why I got wet through.我们既没伞也没雨衣 , 这是我们淋湿的原因 .That is how mice ruin many stores of grain every year.那就是老鼠是怎样每年损害大量粮食的 .That is what he is worried about.那就是他所担心的 .5、由连词 because, as if/as though等引导的表语从句 .It looked as if it was going to snow.看起来

31、好像要下雪了 .That's because we never thought of it.这是因为我们从未想过此事 .It seems as if he didn t know the answer.好像他不知道答案 .可以接表语从句的系动词有：1： be（ being,been,am,is,are,was,were)2: feel , seem , look, appear ,sound, taste , smell3: stand , lie , remain ,keep, stay4: bee ,get , grow , turn ,go ,e, run, fall5: pro

32、ve, turn out系动词的固定搭配:e true, fall asleep, fall ill, go bad, e right, run wild连接词： that / whether /as if /asthough (if不引导表语从句)连接代词： who / whom / whose / which/ what连接副词： when / where / why / how /because注：引导表语从句的连词that间或可以省略.The truth is（ that ） I didn't go there.事实是我没去那儿.考题1 The traditional view

33、 is _ we sleep because our brain is“ programmed ” to make us do so.A. when B. why C. whether D. that答案D解析下划线处之后是包含一个原因状语从句的表语从句,如果看不出它是充当整个句子结构的表语从句将难以把握整个句子的意思.因此,应选择可引导名词性从句且不充当任何成分的that.考题2 You are saying that everyone should be equal, and this is _I disagree.A. why B. where C. what D. how答案B解析下划

34、线处的引导词引导系动词is后的表语从句并在该表语从句中充当地点状语( “ disagree下划线应填入引导词”属于不及物动词where,表语从句“,“ I disagreewhere I disagree”本身是完整的主谓结构”的意思是“我不同意),之处、我不同意的地方”.考题3 I drove to Zhuhai for the air show last week. Is that _ you had a few days off?答案A解析下划线处的引导词引导与系动词is连用的表语从句并在该表语从句中充当原因状语,下划线应填入表示“因此 ”( 指因某种原因所造成的结果) 的引导词why.

35、考题4 _she couldn t understandwas _ fewerand fewerstudentsshowed interest in her lessons.A. What; why B. That; what C. What; because D. Why; that答案A解析第一个下划线处的引导词引导主语从句并在该主语从句中充当宾语,特指她所不理解的事情,应填入关系代词型的引导词what ；第二个下划线处表示“因此 ” “为什么 ”( 指因某种原因所造成的后果,( 指原因、理由 ,由 because由 why 引导对应的名词性从句引导对应的名词性从句),) 而不是应填入引导

36、词why.考题 5 _ made the school had been admitted to key universities. A. What; because B. What; that C. That; what D. That; becauseproudwas _ more than90% of thestudents答案B解析第一个下划线处的引导词引导主语从句并在该主语从句中充当主语,特指令校方骄傲的事情,应选用关系代词型的引导词what ；第二个下划线处引导表语从句表示原因、理由 ,应由 that引导对应的名词性从句考题6 Are you still thinking abou

37、t yesterday Oh, that s _. s game?A. what makes me feel excited B. whatever I feel excited aboutC. how I feel about it D. when I feel excited答案A解析A 选项的意思是“令我感觉激动的事物”；B 选项的意思是“我觉得激动的任何事物”；C 选项的意思是“我对它感觉的方式”；D 选项的意思是“令我感觉激动的时间”. 四个选项中A 最适合跟代表“game”的主语that对应 ,充当表语从句.表语从句与宾语从句的关系不属于的宾语从句和表语从句都属于名词性从句. 其作

38、用跟名词在句中的作用相同. 故充当宾语的句子叫宾语从句,充当表语的句子叫表语从句.宾语从句(1) 对于宾语从句要掌握以下三点语序 :从句的语序必须是陈述句语序,即“主语+谓语”这种形式.时态 :当主句是一般现在时或一般将来时的时候,从句可以是任何时态,而当主句是一般过去时的时候,从句 ,从句时态必须是过去时范围的时态,即 ( 一般过去时,过去进行时,过去完成时,过去将来时).连接词:当从句意思完整,主句意思肯定时,连接词用that,且可以省去,当从句意思完整,主句意思不确定或含否定含意时,常用if或whether(是否),当从句意思不完整时,连接词则是代替不完整部分的特殊疑问词.表语从句在句子

39、中起表语作用的从句叫做表语从句,位于主句系动词的后面. 表语从句的引导词和主语从句的引导词相同. 也是名词性从句的一种.如： What the police want to know is when you enred red the room想知道的是你什么时候进的房间.The The trouble is that we are short of funds困难是我们缺乏资金.警察This This is what we should do这是我们应当做的.That ” s s why I want you to work there那就是我要你在那儿工作的原因.His His first

40、 question was whether Mr. Smith had arrived yet他的第一个问题是史密斯先生到了没有.注意：从句中的疑问句用正常语序,即陈述语序.as as if, as though, becau也可用来引导表语从句.She She seems as if she had done a great thing她看起来好像做了一件大事It It is because you eat too much那是因为你吃得太多了.表从练习一1.The question is _ we will have our sports meet next week.A. thatB.

41、ifC. whenD. whether2 The reason why he failed is _he was too careless.A. becauseB. thatC. forD. because of3.Go and get your coat. It s _you left itA. whereB. thereC. there whereD. where there4 The problem is _to take the place of TedA. who can we getB. what we can getC. who we can getD. that we can

42、get5.What I want to know is _ he likes the gift given by us.A. thatB. ifC. whetherD.不填6.The reason is_I missed the bus.A. thatB. whenC. whyD. what7.That is _ _ we were late last time.A. thatB. whenC. whyD. what8.She looked _ she were ten years younger.A. thatB. likeC. asD. as though9. I fell sick!-I think it is _ you are doing too much.A. whyB. whenC. whatD. because10. The reason why he hasn t e is _.A. because his mother is illB. because of his motherC. that his mother is illD. for his mother is ill11. He was born here.- That is _ he likes the pl