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无含义/在句中不做成分/不可以省.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.（2） 用连词 whether 引导的主语从句: whether有含

2、义(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 will hold a party in the open air tomorrow depends on the weather. Whether she is coming or not doesnt matter too much.（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,

3、担当一定成分.例如：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.要注意和whatever, whoever引导的让步状语从句的区别.Whoever breaks the law should be

4、 punished. （主语从句）（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 come hasnt been

5、 made 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 off.(

6、但当what引导的主语从句表示“的东西”时, 一般不用it作形式主语.)错:It is a book what he wants.对:What he wants is a book. 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 is a f

7、act 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.It is common knowledge that the whale is not a fish.It is no surprise that Bob should have won the gam

8、e.Its a pity that you missed the film. 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; asto

9、nishing, etc.例如：It is doubtful whether she will be able to come.It was really astonishing that 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 computer. It is important that a

10、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; n

11、oted; discussed; required; decided; suggested; demanded; made clear; found out,etc.例如：It is thought that he is the best player.It is estimated that the vase is 2000 years old.It is used to be thought that a new star must be due to a collision between two stars. It has not been made clear when the ne

12、w road is to be opened to traffic.It is said that he was killed in the earthquake. D. It seems（happened / appears / doesnt matter / makes no difference / occurred ）that It 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 mis

13、sed my train.It happened that I saw him yesterday.主从练习1. _ as much as one-fifth of all timber harvested is not used.A. The estimate           B. The estimated   

14、; C. They are estimated       D. It is estimated that2. _ some mammals came to live in the sea is not known.   A. Which      

15、 B. Since        C. Although      D. How 3. _ we have achieved is attributed to the guidance of our parents.   A. Whoever

16、0;    B. Whatever     C. However      D. That 4. _ wealthy does not necessarily mean that a man is greedy.   A. For the 

17、reason that he is      B. Just because he is    C. The reason of being           D. That he is 5. Although _&#

18、160;happened in this developed country sounds like science fiction,  it could occur elsewhere in the world.   A. which        B. what     &#

19、160; C. how           D. it6. _ she had forgotten to take her notebook.   A. That occurred to her         

20、0; B. She occurred that     C. To her that occurred           D. It occurred to her that7. I am sure that _ she said

21、0;is wrong.   A. which        B. all         C. this            D. what8. We lost our way 

22、in the forest, and _ made matters worse was that it was getting dark.  A. that           B. which      C. it   

23、;           D. What9. _ or not is still uncertain.  A. Hes coming                 B. If he 

24、;is coming      C. That coming                 D. Whether hes coming10. Its _ hell be able to come.  A. doubt&

25、#160;whether  B. doubtful     C. doubt it         D. doubtful whether 11. _ he is at work in the heart of the big city or

26、0;at home in the quiet  suburb, Dicks life is tied to machines.  A. Whether       B. Till              C. If &

27、#160;          D. Unless12. _ he saw both surprised and frightened him.  A. That          B. When      &#

28、160;     C. What         D. Which13. _ is  warm sunshine.  A. What do we all need.          B. What all&#

29、160;we need    C. What we need                 D. What we all need14. _ is a pity that he should feel so upset

30、.   A. What         B. That              C. He           D. It15. _ a spoonful&#

31、160;of soil can tell us so much about the structure and early history of the moon.  A. Remarkable                  B.

32、60;Quite remarkably    C. It is remarkable that            D. It is remarkable fact that16. _ you nominate will be elected.   

33、;A. Who         B. Whom             C. Whomever    D. Thats 17. _ book you borrow must be returned within

34、 a week.   A. What       B. Which              C. Whichever     D. Thats 18. _ of us gets home&

35、#160;first starts cooking.   A. Who       B. Which              C. Whichever     D. Anyone1._ makes mistakes must correct the

36、m.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. for 3.When and why he came here _ yet.A. is not known B. are not known C. has not known D. have not known4. _ is no reason for dismissing her.A. Because she was a few minutes late B.

37、 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. Thatthat you had expected B. What that you had expectedC. Thatwhat you had expected D. Whatwhat you had expected6._ we go swimming every day _ us a lot of

38、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 that8.It's uncertain _ the experiment is worth doing.A. if B. that C. whether D. how9._ the boy didn't take medicine made his mother angry.A. That B. What C

39、. 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 camping tomorrow depends on the weather.A. If B. Whether C. That D. Where13._i

40、s going to do the job will be decided by the Party committee.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 us.A. How B. What C. Why D. This16._the house will be built will be discus

41、sed at tomorrow's meeting.A. If B. Where C. That D. What17._you come 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 is a matter of public concern.A. Which B. That C. If D. How20. Who is thi

42、s factory _ some foreign friends visited last Friday?A. that B. where C. which D. the one21.Is this factory you 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. 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

43、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 w

44、hy 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),

45、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 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.问题是它作为日常之用太贵重了.Wha

46、t she couldnt understand was that fewer and fewer students showed interest in her 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, whichever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 w

47、ho 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.就在你原来放的地方.I had neither a raincoat nor an umbrella. Thats 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 h

48、ow 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 didnt know the answer.好像他不知道答案.可以接表语从

49、句的系动词有：1：be（being,been,am,is,are,was,were)2: feel , seem , look, appear ,sound, taste , smell 3: stand , lie , remain ,keep, stay4: become ,get , grow , turn ,go ,come, run, fall5: prove, turn out 系动词的固定搭配:come true, fall asleep, fall ill, go bad, come right, run wild 连接词：that / whether /as if /as t

50、hough (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 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

51、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”属于不及物动词, “I disagree”本身是完整的主谓结构), 下划线应填入引导词where, 表语从句“whe

52、re I disagree”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?A. why B. when C. what D. where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.考题4 _ she couldnt understand was _ fewer and fewer students showed int

53、erest 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”(指因某种原因所造成的后果, 由why引导对应的名词性从句)而不是“为什么”(指原因、 理由, 由because引导对应的名词性从句), 应填入引导词why.考题5 _ made the school proud was _ more than 90% of the student

54、s had been admitted to key universities. A. What; because B. What; that C. That; what D. That; because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 about yesterdays game? Oh, thats _.A. what makes me feel excite

55、d 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

56、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

57、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警察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. 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 question was whether Mr. Smith had arr

58、ived 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. that B. if C. when D. whether2The reas

59、on why he failed is _he was too careless.A. because B. that C. for D. because of3. Go and get your coat. It s _you left itA. where B. there C. there where D. where there4The problem is _to take the place of TedA. who can we get B. what we can getC. who we can get D. that we can get5. What I want to

60、know is _ he likes the gift given by us.A. that B. if C. whether D.不填6. The reason is_I missed the bus. A. that B. when C. why D. what7. That is _ _ we were late last time. A. that B. when C. why D. what8. She looked _ she were ten years younger.A. that  B. like C. as    D. as th

61、ough9.I fell sick!-I think it is _ you are doing too much. A. why B. when C. what D. because 10. The reason why he hasnt come is _. A. because his mother is ill B. because of his mothers being illC. that his mother is ill D. for his mother is ill11. He was born here.- That is _ he likes the place so

62、 much.A. that B. what C. why D. how12.That is _ Lu Xun once lived.A. what B. where C. that D. Why二1_your father wants to know is_ getting on with your studies.A. What; how are you B. That；how you are C. How；that you are D. What；how you are2. The trouble is_we are short of tools. A. what B. that C. h

63、ow D. why that3. America was _was first called “India” by Columbus.A. what B. where C. the place D. there where4. China is becoming stronger and stronger. It is no longer_ . A. what it used to be B. what it was used to being C. what it used to being D. what it was used to be 5. _he really means is _

64、he disagrees with us.A. What that B. That whatC. What what D. That what6. The energy is _ makes the cells able to do their work.A. that B. which C. what D. Such三1. I drove to Zhuhai for the air show last week .Is that_ you had a few days off？A. why B .what C. when D. where 2. I had neither a raincoa

65、t nor an umbrella _I got wet through. A. Its the reason B. Thats why C. Theres why D. Its how3. See the flags on top of the building? That was _ we did this morning. A. when B. which C. where D. what4. - Are you still thinking about yesterdays game? -Oh, thats _.A. what makes me feel excited B. whatever I feel excited aboutC. how I feel about it D. when I feel