Unit主语从句

1、Unit4主语从句 主语从句可以按其引导词的不同分为三类：第一类，用从属连词that引导的主语从句，例如： That we shall be late is certain. That the driver could not control his car was obvious. 这种结构主要是对that从句的内容进行强调，属正式文体，连词that不可以省略；但是在一般情况下，往往使用先行it结构，即用it作形式主语，而把that从句放到后面，这时，在口语中，连词that有时则可以省略。所以上述两句可以改为It is certain that we shall be late. It wa

2、s obvious that the driver could not control his car. 如果整个句子是疑问形式，就只能用先行it结构，例如Is it true that he would take the risk? Is it possible that they will come tomorrow？常使用先行it结构，用that从句作主语的句子有下列几个句型1、It + be + 形容词+that从句： It is clear that he was telling the truth. Its probable that well be a little late.

3、2It + be + 名词词组+ that从句： Its a pity that you cant go with us. 3It + 及物动词+宾语+ that： It worried her a bit that her hair was turning grey. It shocked me that Peter didnt tell anybody where he was. 4It + be +过去分词+ that+从句： It is said that he has been there many times. 5It +seem/happen/appearIt +等不及物动词等+

4、 that从句： It seems that he has lost something.注意:在上述第1和第2两种句型中，that从句前置与使用先行it，that从句后置在意义上没有什么差异；但使用先行it结构较为常见。在第3种句型中，that从句前置在语法上是可能的，但实际上并不常见，通常总是使用先行it结构 . 第4种句型实质上是被动结构，由于that从句不可以位于句首作被动句的主语，所以只能使用先行it结构。第5种句型已经形成了固定的搭配关系，that从句不能前置，只能使用先行it结构，不过，这种结构可以转换为带有不定式的简单句，例如： It happened that I had n

5、o money with me that day. I happened to have no money with me that day. 第二类，用连接代词who、whose、which、what，连接副词when、where、how、why，以及连词whether（或if）引导的主语从句，例如Who was responsible for the accident is not yet clear. It is not yet clear who was responsible for the accident. What he did is not yet known. It is

6、not yet known what he did. Whether it is true remains a problem.It remains a problem whether / if it is true.从以上例句可以看出，这类主语从句可以直接放在句首作主语，也可以使用先行it结构，把主语从句放在后面，两种结构可以互换，意义上无差异，但用if 引导主语从句时，只能采取先行it结构，也就是说if不可以引导置于句首的主语从句.第三类，用what、whatever、where、wherever、whoever、whichever等代词引导的主语从句，例如; What he said a

7、t the meeting encouraged everyone. Whoever fails to see this will make a big blunder.这类从句一般相当于带有定语从句所修饰的名词词组，即在结构上相当于一个名词加上一个定语从句，例如： What he wants to buy is a ten-speed bicycle. The thing that he wants to buy is a ten-speed bicycle. Whoever breaks the law is sure to be punished. Anyone who breaks t

8、he law is sure to be punished.切记，这类主语从句不可以使用先行it结构。 上述第二类主语从句与第三类主语从句尽管在形式上十分相似，但实际上是不同的。第二类结构中用连接代/副词引导的从句系由特殊疑问句转化而来，以whether/if引导的从句系由一般疑问句转化而来，自然含有疑问的意味，例如： When they will have the sports meet is still a question. When will they have the sports meet?Who he is doesnt concern me. Who is he？ Whethe

9、r he will join us wont make too much difference. Will he join us？而第三类结构中的主语从句则没有疑问的意味。试比较下列各句 What caused the accident is a complete mystery. What caused the accident was a broken bottle. What she looks like doesnt matter. What shed like is a digital watch.上述各句中尽管都有一个以what引导的主语从句，但其意义不尽相同；第和句中的主语从句系

10、由“What caused the accident？”和“What does she look like？”转化而来，所以可以改成： It is a complete mystery what caused the accident. It doesnt matter what she looks like.第句中的主语从句含义分别为“The thing that caused the accident”和“The thing which shed like”，所以不含疑问意味，因此不可以说： It was a broken bottle what caused the accident.

11、It is a digital watch what shed like.但是可以说： It was a broken bottle that caused the accident. It is a digital watch that shed like.不过，这已不是主语从句，而是强调结构了。名词性从句通常以“引导词正常陈述句语序”的基本形式出现，有时会省略引导词，例如： Where the meeting is to be held has not been decided. 在哪里开会还没决定。(引导词where 在正常陈述句语序的主语从句中作地点状语) Whether he wil

12、l attend the party is not known.他是否要来参加聚会还不知道。(引导词whether 在正常的陈述句语序的主语从句中不充当任何具体成分，只起引导作用) 考点名词性从句引导词的基本用法下表对高考中常见的名词性从句的引导词进行了总结：名词性从句的引导词引导词是否在名词性从句中充当成分的情况 连接代词： what, which, who, whom, whose 连接副词： when, where, why, how what, which在从句中作主语、 宾语、 表语或定语； who在从句中作主语、 表语； whom在从句中作宾语； whose在从句中作定语； whe

13、n, where, why, how在从句中分别作时间状语、 地点状语、原因状语/方式状语连词that否连词whether, if否名词性从句的引导词在高考中的基本用法详见下面的总结： 1. 引导特殊疑问句的疑问词在转为引导名词性从句时， 即成为连接代词(主要包括what, which, who, whom, whose)或者连接副词(主要包括when, where, why, how)。注意体会如下例句： Choose which you like best. 选你最喜欢的。/ Who has taken away my bag is unknown. 谁拿走了我的包还不知道。/ Havey

14、ou decided whom you are to nominate as your candidate? 你们是否已经决定提名谁做候选人了?/ He asked when Mr. Gilbert would be allowed to go home. 他问什么时候可以允许吉尔伯特先生回家。/ Where we can look up his address is still a problem. 我们在哪儿可以查到他的地址还是个难题。/ Why he did that wasnt quite clear. 他为什么做那件事还不十分清楚。/ How they will solve the

15、serious problem has not been decided. 他们将怎样解决这个严重问题还没有决定。以下两种特殊情况要给予特别关注： (1) what作连接代词引导的名词性从句既可以表示一个问“什么？”的问题，也可以表示相当于“名词/代词关系代词引导的定语从句”结构的意思， 这种特殊用法在语法上被称作“关系代词型的what”，注意体会如下例句：He is not what (=the person that) he was a few years ago. 他不是几年前的他了。/ This is what (=the place that) they call Salt Lake

16、 City. 这就是他们称作盐湖城的地方。/ What (=the place that) is now the North Sahara Desert was once a civilized world. 现在的北部撒哈拉沙漠曾是一个文明世界。/ Our income is now double what (=the income that) it was ten years ago. 我们现在的收入是十年前的两倍。/ The color of the flower is different from what (=the color that) it was in the morning

17、. 花朵(现在的)颜色与它早上的颜色不同。 (2) 带ever后缀的疑问词除引导让步状语从句之外， 还可以引导名词性从句(“no matter疑问词”的结构只能引导让步状语从句， 不可以引导名词性从句)， 注意体会以下例句： Whoever wants to see this film can go with us tonight.无论谁想看这部电影， 今晚都可以和我们一起去。/ You can give the ticket to whomever you like. 你可以把票给任何你想给的人。/ All the books are here. You may borrow whichev

18、er (book) you like. 所有的书都在这儿， 你愿借哪本就借哪本。/ Ill do whatever you ask me to do. 你叫我做什么， 我就做什么。2. that引导名词性从句时后面接完整的陈述句that只起引导名词性从句的作用而不充当该名词性从句中的具体成分；引导宾语从句时that常可省略常可省略常可省略常可省略，但引导主语从句、表语从句、同位语从句时that通常不被省略。例如She hoped (that) he would arrive on time. 她希望他按时到达。(宾语从句) That she was chosen made us very ha

19、ppy. 她被选中了让我们很开心。(主语从句) I have the belief that I will succeed. 我怀有必胜的信念。(同位语从句) that，what引导名词性从句的区别在于： that在其引导的名词性从句中不充当任何成分， 在有的情况下可以省略； what需要在其引导的名词性从句中充当主语、 宾语、 表语或者定语， 而且引导名词性从句的what在任何情况下都不能省略。例如： That he will succeed is obvious. 显然， 他会成功。(引导主语从句的that不在其中充当具体的句子成分) What she told me is not tru

20、e. 她所告诉我的都不是真的。(what在其引导的主语从句中作宾语) 3. whether与if均可以引导表示“是否”之意的名词性从句， 且whether与if均不在这种名词性从句中充当具体的句子成分。在引导宾语从句时whether与if一般可以互换， 但在引导主语从句、 表语从句、 同位语从句、 介词后的宾语从句、 放于句首的宾语从句或者名词性从句中包含or (not) 时通常只能用whether作引导词。注意体会下列例句： I dont know if/whether I can help you. 我不知道我能否帮助你。(宾语从句)/ Whether we can really help

21、 you, I dont know yet. 我们是否真的能帮助你， 我还不知道。(位于句首的宾语从句)/ The teacher worried about whether he had hurt the girls feelings. 老师为是否伤害了那女孩的感情而担心。(介词后的宾语从句)/ The question is whether they can cooperate with us. 问题是他们能否与我们合作。(表语从句)/ The question whether he should come himself or send a substitute must be deci

22、ded upon. 他该亲自来还是派人替他来， 这个问题必须定下来。(同位语从句)/ The little girl asked her father whether she should go to the party or not. 那女孩问她的父亲她应不应该参加这个晚会。(包含or not的宾语从句) 注意： 肯定形式的doubt后面通常接whether/if引导的宾语从句， 否定形式的doubt后面通常接that引导的宾语从句， 例如： I doubt whether its true. 我怀疑它是否是真实的。/ I doubt if that was what he wanted.

23、我怀疑那是否是他所想要的。/ I dont doubt that you are honest. 我不怀疑你的诚实。/ She never doubted for a moment that she was right. 她对自己是正确的这一点从不怀疑。考点8：主语从句的基本用法在句中作主语的名词性从句称为主语从句， 主语从句所对应的谓语动词通常用第三人称单数的形式。为了整个句子的平衡，主语从句经常后置， 并用it充当形式主语(此时， that引导的主语从句若不放在句首， 可以省略引导词that)。例如： What she did is not yet known. 她干了什么尚不清楚。/ W

24、hoever comes is welcome. 不论谁来都欢迎。/ It is a pity (that) we havent contacted for ages. 很遗憾， 我们几年没联系了。/ It has not been decided where the meeting is to be held. 在哪里开会还没决定。/ It doesnt matter whether she will come or not. 她是否来这无关紧要。注意： 不要混淆it 作形式主语指代主语从句与it引导强调句型的情况： it作形式主语代替主语从句主要是为了平衡句子结构， 主语从句的连接词没有变

25、化； it引导的强调句则是对句子某一部分进行强调， 无论强调的是什么成分， 都可用连词that(被强调部分指人时也可用who/whom) / 区分it 作形式主语指代主语从句与it引导强调句型的有效技巧是： 将“It be . that .”中的it be和that去掉后， 句子仍然成立的是强调句， 句子不能成立的是that引导的主语从句。例如： It was my suggestion that made him confident of success. 正是我的建议使他对成功有了自信。 去掉it be和that后可以构成完整的强调句型的原型“My suggestion made him

26、confident of success.”， 因此本句属于强调句。 It is my suggestion that he needs more practice. 他需要更多的练习是我的建议。去掉it be和that后本句讲不通， 因此本句属于主语从句。 用作主语的从句叫做主语从句。 2构成：关联词+简单句3.引导主语从句的关联词有三类(1)从属连词that。如：That they were in truth sisters was clear from the facial resemblance between them. 很明显，她们确是亲姐妹，她们的脸型很相似。 (2)从属连词wh

27、ether。如： Whether hell come here isnt clear. 他是否会来这里还不清楚。(3)连接代词who, whom, whose, what, which, whoever, whatever, whichever 连接副词 where, when, how, why。如： What she did is not yet known. 她干了什么尚不清楚。How this happened is not clear to anyone. 这事怎样发生的，谁也不清楚。Whoever comes is welcome. 不论谁来都欢迎。Wherever you are

28、 is my home - my only home. 你所在的任何地方就是我的家-我唯一的家。 解释： 1.主语从句能用it作形式上的主语。常以it作形式主语的句型有A.It+be+形容词(obvious, true, natural, surprising, good, wonderful, funny, possible, likely, certain, probable, etc.)+that从句。如： It is certain that she will do well in her exam. 毫无疑问她考试成绩会很好。 It is probable that he told

29、her everything. 很可能他把一切都告诉她了。 B.It+be+名词词组(no wonder, an honour, a good thing, a pity, no surprise, etc.)+that从句。如： Its a pity that we cant go.很遗憾我们不能去。 Its no surprise that our team should have won the game. 我们没赢这场比赛真意外。C.It+be+过去分词(said, reported, thought, expected, decided, announced, arranged, e

30、tc.)+that从句。如： It is said that Mr. Green has arrived in Beijing. 据说格林先生已经到了北京。 It is reported that China has sent another man-made earth satellite into orbit. 据报道中国又成功地发射了一颗人造地球卫星。 D.It+seem, happen等不及物动词及短语+that从句。如： It seems that Alice is not coming to the party at all. Alice似乎不来参加晚会。 It happened

31、that I was out that day. 碰巧我那天外出了。 E.It+doesnt matter (makes no difference, etc.)+连接代词或连接副词引起的主语从句。如： It doesnt matter whether she will come or not. 她是否来这无关紧要。 It makes no difference where we shall have the meeting. 我们在哪里开会毫无区别。 F.当that引导的主语从句出现在疑问句中时，要以it作形式主语，而把主语从句后置。如： Is it true that the scient

32、ist will give us a lecture next week? 下周那位科学家将给我们作报告是真的吗？ Does it matter much that they will not come tomorrow? 他们明天不来很要紧吗？ G.当主语从句出现在感叹句中时，要以it作形式主语，而把主语从句后置。如： How strange it is that the children are so quiet! 孩子们这么安静真奇怪！ 2注意连接代词whoever, whatever, whichever等引导主语从句的含义 Whoever comes will be welcome.

33、 (whoever=the person who) 来的人将受到欢迎。 Whatever he did was right. (whatever=the thing that) 他所做的事情是正确的。 Whichever of you comes in will receive a prize. (whichever=anyone of you who) 你们当中不论哪个进来将会得到奖励。 主语从句 主语从句(Subject Clause)定义:在复合句中充当主语的句子叫做主语从句.第一部分：常规主语从句，即句子在复合句中充当一个主语主语从句的时态：不受主句的时态影响和限制。（1）That h

34、e finished writing the composition in such a short time surprised us all.（2）Whether we will go for an outing tomorrow remains unknown.（3）Who will be our monitor hasnt been decided yet.（4） Whom we must study for is a question of great importance.（5）What caused the accident remains unknown.（6）Whatever

35、 you did is right.（7）Whose watch was lost is unknown.（8）What we need is time.（9）What we need are good doctors.小结: 1)引导主语从句连词有that,whether,who,what,whatever等 （2)连词位于句首不能省略3)主语从句大多数情况下视为三单,但也有例外,如例9第二部分：为了防止句子头重脚轻，通常把形式主语it放在主语位置，真正主语搁置于句末（1）It is certain that he will win the match. （2）It is true that

36、 he has made a very important discovery in chemistry.（3）It is very likely that they will hold a meeting.（4）It is strange that he should do that. （5）It is important that we all should attend the meeting.（6）It is strange that the man should have stuck to his silly ideas.（7）It is a pity that we wont be

37、 able to go to the south to spend our summer vacation.（8）It is still a mystery what caused the accident.（9）It is said that he has gone to shanghai.(=He is said to have gone to shanghai)（10）It is known to all that the gun powder was first invented by the Chinese.（11）It is suggested that the work shou

38、ld be done with great care.（12）It seems that he has seen the film.(=He seems to have seen the film)（13）It happened that the two cheats were there. (=The two cheats happened to be there)小结: 1)以that 引出的主语从句,常以形式主语it引导. It is +形容词/名词/某些动词ed + that 从句.（2) 在有些that从句中要用虚拟语气 (should+do/should+have done)例句4

39、,5,6,11.主语从句与宾语从句两者的用法和在句中的作用是不同的，下面从它们的各自用法，介绍：） 一主语从句主语从句 定义:在句子中担当主语的是一个从句,这个从句就叫做主语从句。主语从句是在复合句中充当主语的从句，通常放在主句谓语动词之前或由形式主语it代替，而本身放在句子末尾1. It 作形式主语和it引导强调句的比较It 作形式主语代替主语从句，主要是为了平衡句子结构，主语从句的连接词没有变化。而it引导的强调句则是对句子某一部分进行强调，无论强调的是什么成分，都可用连词that。被强调部分指人是也可用who/whom。例如： It is a pity that you didnt go

40、 to see the film. 2. 用it 作形式主语的结构 (1) It is 名词从句It is a fact that 事实是 It is an honor that 非常荣幸It is common knowledge that 是常识 (2) it is 形容词从句It is natural that 很自然It is strange that 奇怪的是 (3) it 不及物动词从句It seems that 似乎It happened that 碰巧 (4) it is过去分词从句 It is reported that 据报道It has been proved that

41、已证实 3. 主语从句不可位于句首的五种情况 (1) if 引导的主语从句不可居于复合句句首。 (2) It is said , (reported) 结构中的主语从句不可提前。例如： It is said that President Jingo will visit our school next week. (3) It happens, It occurs 结构中的主语从句不可提前。例如： It occurred to him that he failed in the examination. (4) It doesnt matter how/whether 结构中的主语从句不可提前

42、。例如： It doesnt matter whether he is wrong or not. (5) 含主语从句的复合句是疑问句时，主语从句不可提前。例如： Is it likely that it will rain in the evening? 4. What 与that 在引导主语从句时的区别What 引导主语从句时在从句中充当句子成分，如主语宾语表语，而that 则不然。 二：宾语从句的几个特征1引导词：whatwhichwhosewhenwhetherifwhere2语序：宾语从句必须是用陈述语句。如：I think that you must work harder.宾语从

43、句的引导词、连接词的区别、否定转移等现象。(1)表达时间的几个句型：一般用when或者是what time： What time will the train leave?由于时刻都是固定的，也可以用一般现在时代替一般将来时： What time does the train leave? (2)时间的表达方式：8：19(nineteen past eight),7:57(three to eight)，在时间的中间也可以加上分的单词(minutes) (3)had better +动词原型。意思是提要求，建议。但是上下级不能用这种方式，因为语气太重：You had better give u

44、p smoking . (4)sb leave sth +地点I left my book in my classroom yesterday. (5)may I have your name(addressage)?一般询问对方的年龄、名字等，不要习惯以前的问法，这样很不礼貌，而是要采访上面的问法。以前的习惯是：how old are you? whats your name? (6)修饰名词的代词次序：限-描-大-形-年-颜-籍-物-类+名词： this is a bridge. This is a beautiful bridge补充：从句的语序永远是陈述句。一、主语从句的引导词 主语从

45、句通常由连词that和whether、连接代词或连接副词以及关系代词型what引导。1. that引导 That he is still alive is a wonder. 他还活着，真是奇迹。 That we shall be late is certain. 我们要晚了，这是确定无疑的。 That he should have ignored the working class was natural. 他忽视工人阶级是很自然的。 That she is still alive is a consolation. 她还活着是使人感到宽慰的That she became an artist

46、 may have been due to her fathers influence. 她成为画家可能是受她父亲的影响That you are coming to London is the best news I have heard this long time. 你将来伦敦是好久以来我听到的最好消息。 That she was chosen made a tremendous stir in her village. 她被挑选上，在她村子里引起很大轰动。 2. whether引导 Whether it will do us harm remains to be seen. 是否对我们有

47、害还要看一看。Whether they would support us was a problem. 他们是否会支持我们还是一个问题。 3. 连接代词引导 Whoever is top from wins the game when two matched players meet. 两强相争勇者胜。 Whichever (of you) comes in first will receive a prize. 无论(你们)谁先到都可以得奖Whichever you want is yours. 你要哪个哪个就是你的。 4. 连接副词引导 When we arrive doesnt matt

48、er. 什么时候到没有关系。 How it was done was a mystery. 这是怎样做的是一个谜。 How this happended is not clear to anyone. 这件事怎样发生的，谁也不清楚。 How many people we are to invite is still a question. 邀请多少人还是一个问题。 Where I spend my summer is no business of yours. 我在哪里过暑假不关你的事。 5. 关系代词型what引导 What we need is money. 我们需要的是钱What I w

49、ant to know is this. 我想知道的就是这一点Whats done is done. 事已成定局。What he says is not important. 他说的话并不重要。What I am telling you is mere impressions. 我和你说的都不过是一些印象而已。 What make the river more beautiful are the lotus plants growing in the water. 为河水增色的是水里的荷花。 What you need is a good-sized canvas bag. 你需要的是一个比较大的帆布袋。 What I am afraid of is their taking him to Portugal. 我担心的是他们把他带到葡萄牙