主语从句讲解及练习
主语从句
一、名词性从句概述：
在句子中起名词作用的句子叫名词性从句(Noun Clauses）。名词性从句的功能相当于名词词组, 它在复合句中能担任主语、宾语、表语、同位语、介词宾语等，因此根据它在句中不同的语法功能，名词从句又可分别称为主语从句、宾语从句、表语从句和同位语从句。
名词性从句的连词
连接词：that，if/whether(是否)，
连接代词：what, whatever, who, whoever, whom, whomever, whose, which, whichever
连接副词：when, where, how, why, whenever, wherever, however
二、主语从句的连词分三类
（1）从属连词引导的主语从句（that whether if）
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。That 引导主语从句通常用it 作形式主语。
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.
whether 引导的主语从句: whether有含义(是否)/在句中不做成分/不可以省。
注意：引导主语从句，在开头不能用if，只能用whether。
Whether we will hold a party in the open air tomorrow depends on the weather.
Whether she is coming or not doesn’t matter too much.
It’s uncertain whether/if he will come. {不是在句首}
（2）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：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。
如：
Whoever breaks the law should be 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. ）
（3）用连接副词when, where, why, how引导的名词性从句(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 hasn’t been made pubic.
三、it 作形式主语的主语从句
有时为了考虑句子平衡，通常在主语从句处使用形式主语it，而将真正的主语从句移至句末。这分四种情况：
(1)对于以连词that引导的主语从句，通常用形式主语it替代主语从句：
It 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 common knowledge that ………是常识
类似的名词还有：a pity；a wonder；a good thing；no wonder；surprise等。
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 game.
It’s a pity that you missed the film.
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; astonishing, etc.
1.It is doubtful whether she will be able to come.
2.It was really astonishing that he refused to talk to you.
3.It is essential that he should be here by the weekend.
4.It is necessary that you （should）master the computer.
5.It is important that a student learn English well.
6.It is clear that they badly need help.
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。(例句：3，4，5)
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 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 new road is to be opened to traffic.
It is said that he was killed in the earthquake.
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 missed my train.
It happened that I saw him yesterday.
(2)对于以连接代词(副词)引导的主语从句，可以使用形式主语代主语从句，也可直接在句首使用主语从句：
Whether they would support us was a problem.
他们是否会支持我们还是一个问题。
It was a problem whether they would support us.
他们是否会支持我们还是一个问题。
It remains to be seen whether it will do us harm or good.
它对我们是利是害，还得看看再说。
(3)对关系代词型what引导的主语从句，通常直接将主语从句放在句首。如：
What we need is money. 我们需要的是钱。
What I want to know is this. 我想知道的就是这一点。
有时也可将助用形式主语。如：
It is clear enough what he meant. 他是什么意思很清楚。
(4)如果句子是疑问句，则必须用带形式主语it的结构：
Is it true that he is the girl’s father? 他是那女孩的父亲，是真的吗？
How is it that you are late again? 你怎么又迟到了？
四、连词that的省略问题
引导主语从句的连词that 有时可省，有时不能省，其原则是：若that引导的主语从句直接位于句首，则that不能省略；若that引导的主语从句位于句末，而在句首使用了形式主语it，则that可以省略：
That you didn’t go to the talk was a pity. 很遗憾你没去听报告。(that不可省)
It was a pity (that) you didn’t go to the talk. 很遗憾你没去听报告。(that可省)
五、高考题：
1、It never occurred to me_____you could succeed in persuading him to change his mind.(陕西高考) A．which B．what
C．that D．if
解析句意为：我从未想过你会成功地说服他改变主意。that引导了主语从句，前面的it是形式主语。
答案 C
2、________was most important to her，she told me，was her family.(山东卷)
A．It B．This C．What D．As
解析what引导主语从句，what在从句中作主语。
答案 C
3、It's obvious to the students________they should get well prepared for their future.(天津卷) A．as B．that C．which D．whether
解析it为形式主语，that引导主语从句，不作成分，只起连接作用。
答案 B
4、________is known to us all is that the 2008 Olympic Games have taken place in Beijing. A．It B．As C．What D．Which
解析what引导主语从句，并在从句中作主语。
答案 C
5、________some people regard as a drawback is seen as a plug by many others.(2010·北京) A．Wheter B．What C．That D．How
解析what引导主语从句，并在从句中作主语。
答案 B
主语从句练习题
1.________ makes mistakes must correct them.
A. What
B. That
C. Whoever
D. Whatever
2. 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 known
4. ________ is no reason for dismissing her.
A. Because she was a few minutes late
B. Owing to a few minutes late
C. The fact that she was a few minutes late
D. Being a few minutes late
5. ________ Tom liked to eat was different from ________.
A. That…that you had expected
B. What …that you had expected
C. That…what you had expected
D. What…what you had expected
6.________ we go swimming every day ________ us a lot of good.
A. If...do
B. That...do
C. If...does
D. That...does
7.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. how
9.________ the boy didn't take medicine made his mother angry.
A. That
B. What
C. How
D. Which
10.____ we can't get seems better than ____ we have.
A. What, what
B. What, that
C. That, that
D. That, what
11.____ you don't like him is none of my business.
A. What
B. Who
C. That
D. Whether
12..____ we'll go camping tomorrow depends on the weather.
A. If
B. Whether
C. That
D. Where
13._________is going to do the job will be decided by the Party committee.
A. That
B. Why
C. How
D. Who
14._______we'll finish translating the book depends on the time.
A. When
B. Why
C. What
D. That
15.______he won't go there is clear to all of us.
A. How
B. What
C. Why
D. This
16.______the house will be built will be discussed at tomorrow's meeting.
A. If
B. Where
C. That
D. What
17. ._______you come or not is up to you.
A. What
B. If
C. Why
D. Whether
18.._______makes mistakes must correct them.
A. Who
B. Anyone
C. Whoever
D. Anybody
19.._______team will win the match is a matter of public concern.
A. Which
B. That
C. If
D. How
20..________leaves the room last ought to turn off the lights.
A. Anyone
B. The person
C. Whoever
D. Who
答案：1~5 CBACD 6~10DDCAA 11~15 CBDAC 16~20 BDCAC
名词性从句之主语从句讲解
名词性从句---主语从句 1. What is needed for the space trip is careful preparation. 2. Her wish is that she can lose weight soon. 3. I think that woman can reach every high achievements in many fields of science. 4. We were very excited at the news that our team had won. 引导名词性从句的关联词可分为三类： 一．从属连词：that（无任何词意） whether, if（均表示“是否”表明从句内容的不确定性） as if ,as though（均表示“好像”，“似乎”）以上在从句中均不充当任何成分二．连接代词：what, who, whom, which，whose, whatever, whoever, whichever(作主宾表定) 三．连接副词：when, where, how, why(作状语) I.主语从句 1.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。 2.位置：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。 3.引导主语从句的关联词： (1)从属连词that,whether,if (在从句中不充当成分，仅起连接作用) That Jack won the match yesterday surprised us. Whether he’ll come here isn’t clear. (此处不能用if) (2)连接代词who, whom, whose, what, which, whoever, whatever, whichever(充当主宾表定) What she did is not known. Whoever comes is welcome. (3)连接副词where,when,how,why(在从句中充当状语) How this happened is not clear to anyone. When the meeting will be held is decided by our manager. 4.有时为了避免头重脚轻，常用it作形式主语，而把真正主语放在句子末尾。 How the book will sell depends on its author. = It depends on its author how the book will sell. That he is the best student in the class is obvious. = It is obvious that he is the best student in the class. 用it作形式主语的几种常见结构： (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 is ＋不及物动词＋从句 It seems that… 似乎… It happened that… 碰巧… It ap pears that… 似乎… (4) It ＋过去分词＋从句
名词性从句用法详解
名词性从句用法详解 一、概说名词性从句，即指性质相当于名词的从句，它包括主语从句、宾语从句、表语从句和同位语从句。从高考的考查的实际情况来看，名词性从句考得最多的是宾语从句，其次是主语从句，再次是表语从句，而同位语从句则很少考查。 二、名词性从句的一般引导词 1. 连接词 that 只起连接作用，没有任何意思，也不充当句子成分，在宾语从句中可省略，但引导其他名词性从句时通常不省略。如： I hope (that) you enjoy your holiday. 希望你假期过得好。（宾语从句可省） That he likes you is very obvious. 很显然他喜欢你。（That引导主语从句不能省） 2. 连接词 whether 也不充当句子成分，但有自己的意思，表示“是否”；引导宾语从句时，可换成 if，但引导其他名词性从句时不能换成 if。 He asked whether [if] I would show him the way. 他问我是否可以给他带路。 Whether it will do us harm remains to be seen. 是否对我们有害还要看一看。(引导主语从句，不能用 if 代替 whether) 3.连接代词 who(m), whose, which, what 等，均有各自的意义，在从句中作主语、宾语、定语等。如： That’s why she wanted to leave. 这就是她想离开的原因。 When we arrive doesn't matter. 什么时候到没有关系。 Tell me which one you like best. 告诉我你最喜欢哪一个。 4.连接副词 when, where, why, how 等，也各自有自己的意义，在从句中作状语。如： The question is how we should carry out the plan. 问题是怎样执行这个计划。 When she’ll be back depends much on the weather. 她什么时候回来在很大程度上要看天气。 Why he did it will remain a puzzle forever. 他为什么这样做将永远是一个谜。 三、名词性从句的重要引导词 1. what 用于引导名词性从句是一个十分重要的引导词，它可引导主语从句、宾语从句和表语从句，但不用于引导同位语从句。它引导的名词性从句有两个意思是：一是表示“什么”，带有疑问意味；二是表示“…所…的”，相当于一个先行词后接一个关系代词。 如： I don’t know what you want. 我不知道你想要什么。 I don’t know what you want is this. 我不知道你所想要的是这个。 2. whoever, whatever, whichever 等也可引导名词性从句，其意分别为“所…的一切事或东西”、“任何…的人”、““…的任可人或物”等。如： Whoever wants the book may have it. 任何人要这书都可拿去。 I’ll do whatever I can to help him. 我们将尽我们所能来挽救他。 注意以下受汉语意思影响而弄错的句子： 任何人来都欢迎。 误：Who comes will be welcome. / Anyone comes will be welcome. 正：Whoever comes will be welcome. / Anyone who comes will be welcome. 另外，它们也可引导让步状语从句，其意为“无论…”、“不管…”，其意相当于no matter who [what, which]。如： Whatever happens, you must be calm. 不管发生什么情况，你都必须镇静。(whatever = no matter what)
主语从句详解及练习-附答案
语法要点剖析 一、名词性从句 主语从句、表语从句、宾语从句、同位语从句，在整个句子中所起的作用，相当于一个名词。因此，这四种从句通称为名词性从句。 引导名词性从句的连接词可分为三类： 连接词：that, whether, if （不充当从句的任何成分） 连接代词：what, whatever, who, whoever, whom, whose, which. 连接副词：when, where, how, why 1. 主语从句 作句子主语的从句叫主语从句。主语从句通常由从属连词that，whether，if 和连接代词what，who，which，whatever，whoever以及连接副词how，when，where，why等词引导。that在句中无词义，只起连接作用；连接代词和连接副 词在句中既保留自己的疑问含义、又起连接作用，在从句中充当从句的成分。例如： What he wants to tell us is not clear. 他要跟我们说什么，还不清楚。 It is known to us how he became a writer. 我们都知道他是如何成为一名 作家的。 Where the English evening will be held has not yet been announced. 英语晚会将在哪里举行，还没有宣布。 有时为避免句子头重脚轻，常用形式主语it代替主语从句作形式主语放于句首，而把主语从句置于句末。主语从句后的谓语动词一般用单数形式。常用句型如下： （1）It + be + 名词+ that从句（2）It + be + 形容词+ that从句 （3）It + be + 动词的过去分词+ that从句（4）It + 不及物动词+ that 从句 另注意在主语从句中用来表示惊奇、不相信、惋惜、理应如此等语气时，谓语动词要用虚拟语气“(should) +do”，常用的句型有： It is necessary (important, natural, strange, etc.) that … It is a pity (a shame, no wonder, etc.) that… It is suggested (requested, proposed, desired, etc.) that… 2. 宾语从句 名词句用作宾语的从句叫宾语从句。引导宾语从句的关联词与引导主语从句表语从句的关联词大致一样，在句中可以作谓语动词或介词及非谓语动词的宾语。 1. 由连接词that引导的宾语从句 由连接词that引导宾语从句时，that在句中不担任任何成分，在口语或非正式的文体中常被省去，但如从句是并列句时,第二个分句前的that不可省。例如：He has told me that he will go to Shanghai tomorrow.他已经告诉我他明天要去 上海。 We must never think (that) we are good in everything while others are good in nothing. 我们决不能认为自己什么都好，别人什么都不好。
高考英语主语从句讲解
高考英语主语从句 定义：用作主语的从句叫主语从句，它是名词性从句之一。主语从句的时态：不受主句的时态影响和限制。引导主语从句的连接词有： 从属连词: that, whether； 连接代词: who (whoever), whom, whose, what (whatever)和which (whichever)； 连接副词: when, where, how和why。 连接词： 1. 从属连词：that，whether 1）that引导主语从句只起引导作用，在主语从句中不充当任何成分，that本身无实际意义，但不能省略。2）whether意为“是否”，放在句首句末皆可。由whether引导的名词从句做主语，表语，介词宾语，同位语时！不可用if代替。 a.That price will go up is certain. b. Whether they would support us was a problem. 他们是否会支持我们还是一个问题。 2. 连接代词who ，what ，which, whatever, whichever, whoever (Who, whom, which, what可以和ever构成合成词，和what一样引导从句，ever起到强调作用。此类主语从句不能用形式主语it引导，它们在句子中担任成分，不能省略，语序为陈述语序，既有疑问含义,又起连接作用,同时在从句中充当各种成分。 Which side will win is not clear. Whoever breaks the law will be punished. Whatever he did is right. Who killed the scientist remains a question. 1）What和that引导的主语从句的区别：that 只起引导作用，不充当任何成分，没有意思。What 不仅起引导作用，还要充当一定成分(主语、宾语或表语)，意思是：“什么”。 What we need is money. That he will come is certain. 2）whatever / whoever的用法（~ever=no matter ~---让步状语从句中） whatever / whoever可以引导主语从句,并在句中作主语、宾语、表语等,不含疑问意义。whatever相当于anything that; whoever 相当于anyone who。例如: Whoever(Anyone who) wants to enter into this school must take the exam. Whatever(Anything that) she did was right. 3. 连接副词when，where，how，why等。既有疑问含义,又起连接作用,同时在从句中充当各种成分。How this happened is not clear to anyone. When he will be back depends on the weather. When we’ll start tomorrow will be told soon. Where the test will be given is not yet decided. 4. 主语从句后置：为了避免主语冗长,句子头重脚轻,经常用it 作形式主语,主语从句放在后面作真正的主语. 例: That we shall be late is certain. -- It’s certain that we shall be late. 1）用it 作形式主语的结构 A. It + be + 形容词+ that 从句 (obvious, true, surprising, good, wonderful, funny, possible, likely, certain, probable, etc.) 如：It is certain that she will do well in her exam. B. It + be + 名词词组+ that 从句(an honour, a fact, a pity, etc）如： It is a pity/shame that... 遗憾的是…… It is a surprise that…令人惊奇的是… It is a fact that… …是事实It is common knowledge that… …是常识 It’s a pity that we can’t go. C. It + be + 过去分词+ that 从句(said, reported, thought, expected, decided, announced, etc。）如：It is said that Mr. Green has arrived in Beijing. D. It + 不及物动词或短语+ that 从句( seem，happen, doesn’t matter ,turn out）。如： It happened that I was out that day. It doesn’t matter whether she will come or not. 2) 对于以连接代词(副词)引导的主语从句,可以使用形式主语代主语从句,也可直接在句首使用主语从
高考英语专项复习主语从句详解
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 doesn’t 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, 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
高中主语从句讲解及其练习
主语从句 一、主语从句的连词分三类 （1）从属连词引导的主语从句（that whether if） 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。That 引导主语从句通常用it 作形式主语。 例如：That you will win the medal seems unlikely. That she survived the accident is a miracle. whether 引导的主语从句: whether有含义(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不能在开头，只能用whether。 Whether we will hold a party in the open air tomorrow depends on the weather. Whether she is coming or not doesn’t matter too much. （2）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：What you need is more practice. 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。 如：Whoever breaks the law should be 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. ） （3）用连接副词when, where, why, how引导的名词性从句(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 hasn’t been made pubic.
宾语从句用法详解
宾语从句用法详解 在句子中起宾语作用的从句叫做宾语从句。宾语从句分为三类：动词的宾语从句，介词的宾语从句和形容词的宾语从句。 一、宾语从句用法 宾语从句的时态： 1．主句用一般现在时，从句可用任意时态。可归纳为“主现从不现” 2．主句用过去时，从句用过去某个时态。可归纳为“主过从句过” 3．主句用过去时，从句是科学真理、客观常识、名人格言时用一般现在时。 4．情态动词could/would用于，“请求”，表示委婉、客气的语气时，从句不受主句的约束。 宾语从句的连接词 从属连词 连接宾语从句的从属连词主要有that, if, whether. that引导表示陈述句的宾语从句， if和whether，whether...or not引导表示“是否”的一般疑问句的宾语从句. He told me (that ）he would go to college the next year 他告诉我他明年上大学. I don’t know if there will be a bus any more. 我不知道是否还会有公交车. Nobody knew whether he could pass the exam. 没有人知道他是否会通过考试. who,whom,whose,what,whoever,whomever,whosever,whatever,whichever等. 连接代词一般指疑问，但what,whatever除了指疑问外，也可以指陈述. Do you know who has won Red Alert game 你知道是谁赢得了红色警戒的游戏么？ The book will show you what the best CEOs should know. 这本书会告诉你最好的执行总裁该了解什么. Have you determined whichever you should buy, a Motorola or Nokia cell phone
初中语法 主语从句讲解及(完整版)
主语从句：即在复杂句中充当主语成分的句子 例如"That he finished writing the composition in such a short time surprised us all"，他在很短的时间内写完作文让我们都很惊讶, 此复合句主要描述的是某事让我们惊讶，某事就是该复合句的主语，因此"That he finished writing the composition in such a short time" 便是该复合句的主语从句。 主语从句使用陈述语序，其通常结构为“引导词+ 主语+ 谓语+ 其他成分”；但当连接代词同时充当从句主语时，其结构为“连接代词+ 谓语+ 其他成分”。 时态：主语从句的时态不受主句时态的影响和限制 引导主语从句的连词主要有: 从属连词:that、whether （只起连接作用，不充当句子成分） 连接代词:who、whoever、whom、whose、what 、whatever 、which 、whichever （既有连接作用，又做从句的主语、宾语、表语或定语） 连接副词:when、where 、how 、why whenever、wherever（既有连接作用，又做从句的状语） 例句： 1. that引导
例句：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。 2. whether引导 例句：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 例句：Whoever is top from wins the game when two matched players meet. 两强相争勇者胜。 4. 连接副词引导 例句：How this happended is not clear to anyone. 这件事怎样发生的，谁也不清楚。 5. what引导 例句：What struck me was that they have all suffered a lot. 给我很深印象的是他们都受过很多苦。 一、形式主语it 有时为了考虑句子平衡，避免句子头重脚轻,通常在主语从句处使用形式主语it，而将真正的主语从句移至句末。 常用句型如下： (1)It + be + 形容词+ that 从句
主语从句详解及练习_附答案
高二年级语法要点剖析（李翌洋） 一、名词性从句 主语从句、表语从句、宾语从句、同位语从句，在整个句子中所起的作用，相当于一个名词。因此，这四种从句通称为名词性从句。 引导名词性从句的连接词可分为三类： 连接词：that, whether, if （不充当从句的任何成分） 连接代词：what, whatever, who, whoever, whom, whose, which. 连接副词：when, where, how, why 1. 主语从句 作句子主语的从句叫主语从句。主语从句通常由从属连词that，whether，if 和连接代词what，who，which，whatever，whoever以及连接副词how，when，where，why等词引导。that在句中无词义，只起连接作用；连接代词和连接副词在句中既保留自己的疑问含义、又起连接作用，在从句中充当从句的成分。 例如： （1）What he wants to tell us is not clear. 他要跟我们说什么，还不清楚。 It is known to us how he became a writer. 我们都知道他是如何成为一名作家的。 Where the English evening will be held has not yet been announced. 英语晚会将在哪里举行，还没有宣布。 注意：有时为避免句子头重脚轻，常用形式主语it代替主语从句作形式主语放于句首，而把主语从句置于句末。主语从句后的谓语动词一般用单数形式。常用句型如下： （1）It + be + 名词+ that从句 （2）It + be + 形容词+ that从句 （3）It + be + 动词的过去分词+ that从句 （4）It + 不及物动词+ that 从句 另注意在主语从句中用来表示惊奇、不相信、惋惜、理应如此等语气时，谓语动词要用虚拟语气“(should) +do”，常用的句型有： It is necessary (important, natural, strange, etc.) that … It is a pity (a shame, no wonder, etc.) that… It is suggested (requested, proposed, desired, etc.) that…
高中英语语法主语从句讲解及练习
名词性从句之主语从句 一、名词性从句概述：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、主语从句定义： 在句中起主语作用的从句称为主语从句。 引导主语从句的连接词主要有：单纯连词（that, whether/ if）、连接代词(what, whatever, who, whoever, whom, whose, which, whichever等)和连接副词(when, where, why, how, whenever, wherever, however等)。 1)that引导的主语从句 （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.你能得奖看起来不大可能。 That light travels in straight lines is known to all. 众所周知，光沿直线传播。 That you don’t like him is none of my business.你不喜欢他不管我的事。（2）形式主语it替代主语从句位于句首，that引导真正的主语从句会放到句子的后面。常用的句式主要有如下几种： 1.It+ 系动词+形容词+that从句。 如： 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; astonishing, etc. 例如：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 can not go on like this. It is necessary that you （should）master the computer.
英语从句讲解
Simple sentence Compound sentence Complex sentence 从句：名词性从句（主语从句，宾语从句，表语从句，同位语从句） 形容词性从句(定语从句) 副词性从句（状语从句） 英语中六大从句用法总结 在句子中起名词作用的各种从句，统称为名词性从句 1.主语从句subjective clause 一般由what, who, which, why, how, when, which, whether…or…等引导，如果从句较长，谓语又较短，可用it作形式主语，而将从句放在句末。常见的句型有： It is self-evident that… 很明显的是 It goes without saying that… 不用说 It is asserted that．．．有人主张…… It is believed that．．．据信…… It is generally considered that．．．人们普遍认为…… It is hoped that．．．人们希望…… It is reported that．．．据报道…… It is said that．．．据说…… It is supposed that．．．据推测．．．
It is well-known that．．．众所周知…… It must be admitted that．．．必须承认…… It cannot be denie d that… 不可否认…… It must be pointed out that．．．需指出的是…… It was told that．．．据传…… It will be said that．．．有人会说…… It follows that… 由此可见 It is inappropriate that… ……是不合适的 2)what引导的主语从句表示“...的东西时”，一般不用it作形式主语。 What we lack is experience. 3)what, who, when, why, whether等词含有各自的疑问意义，但它们引导的主语从句，都用陈述语序。 How the plan is to be carried out should be discussed again. I did know why I felt like crying. 2.宾语从句objective clause 1）宾语从句可位于及物动词、介词和某些形容词后。连词that常可省略。介词后一般接疑问词引导的宾语从句。in
主语从句详细讲解及综合练习
主语从句 一、概念：在复合句中起主语作用得从句叫主语从句。 （一）连接词 从属连词：that、whether； 关系代词：who, what, which , whom, whose, whatever, whoever, whomever, whichever； 关系副词：when, where, how, why, however, whenever, wherever等； 例：What he said is true、 That you don’t like him is none of my business、 Whether the football game will be played depends on the weather、 主语从句得时态：不受主句得时态影响与限制。 （1）______ he finished writing the composition in such a short time ______(惊讶) us all、（2）______we will go for an outing tomorrow ______（remains，remained）unknown、（3）______ will be our monitor ______(be) decided yet、 （4）______we must study for ______ (be) a question of great importance、 （5）______ caused the accident ______（remains，remained）unknown、 （6）______ you did ______ (be)right、 （7）______ watch ______(be) lost is unknown、 （8）______we need ______(be) time、 （9）______ we need ______(be) good doctors、 小结: （1)主语从句得时态：不受主句得时态影响与限制。 （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 1、从属连词that，whether引导得主语从句。 从属连词that，whether在主语从句中得作用只就是引导主语从句，在从句中不担任成分，不能省略。 例：__________ they will go is certain、 __________ she will come or not is still a question、 __________ she's coming or not doesn't matter too much、 2、it作形式主语引导主语从句。 如果主语从句太长，为避免句子结构头重脚轻，我们可用it作形式主语，而把主语从句放在主句谓语部分之后。That引导得主语从句可用it代替，that 不可省略。 用作it作形式主语得结构： （1）It is/was +形容词+that 从句 It’s natural that…很自然……It’s obvious that …显而易见…… It’s fortunate that …幸运得就是It’s (im)possible…（不）可能…… It’s unlikely that…不可能It’s strange that…奇怪得就是…… （2）It is/was +名词+that 从句 It’s a pity that…遗憾得就是……It’s a fact that …事实就是…… It’s good news that…就是好消息……It’s a wonder that…不足为奇…… It’s an honour that…非常荣幸……It’s a shame that…真就是可耻…… It’s common knowledge that …就是常识… （3）It +不及物动词+that 从句 It seems that…似乎……It happened that…碰巧…… It appears that…瞧来……It turns out that…结果…… （4）It is/was +过去分词+that 从句 It’s not known that………不得而知It’s said that…据说……
主语从句的用法 主语从句讲解
主语从句的用法主语从句讲解 一个句子在复合句中充当一个主语，那么这个句子就是主语从句。下面小编就给大家介绍主语从句的用法。 主语从句的用法 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 didn’t go to see the film. It is +名词+从句 It 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 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. 这一切是怎么发生的是个谜。 It is common knowledge that the whale is not a fish. 鲸鱼不是鱼，这是常识。 It is no surprise that Bob should have won the game. 鲍勃会赢得这场比赛，这不足为奇。 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; astonishing, etc. 例如：It is obvious that conductors and insulators are both important in industry.
高中英语知识讲解 主语从句
主语从句 概念引入 That you will win the medal seems unlikely. 你想获得奖牌看起来是不可能的。 Whether she is ing or not doesn’t matter too much. 她来不来都无关紧要。 What I want to know is this. 我想知道的就是这事。 When the plane is to take off has not been announced . 飞机何时起飞还没有宣布。 观察上面四个句子可以看出，黑体词部分都有连接词连接，后面都是一个谓语动词，黑体词部分都是整个句子论述的主体部分，它们就是我们本单元要学习的主语从句。 语法讲解 什么是主语从句？ 【高清课堂：367100名词性从句（一）主语从句】 在复合句中由一个句子作主句的主语的从句叫主语从句。 What matters is not winning but participating. I don’t know why he is always finding fault with me. My hometown is no longer what it used to be ten years ago. He expressed his hope that he would e to Chengdu again. 其中划横线的部分就是名词性从句。 主语从句引导词： 1. 由what等代词引导的从句,表示“所……的(东西)”，实际上等于一个先行词加上一个定语从句，也可以由-ever等代词引导。 比如: What they are talking about is nothing valuable. What I really want is to have a good rest. Whatever she did is wrong. 比较：Whatever she did, she is wrong. Whoever passes the exam can get 50 yuan. 比较：Whoever passes the exam, I will give him 50 yuan. 比较：Who passes the exam is still not clear. 2. 由that引导的主语从句,通常用形式主语it来代替。 That he has disappeared worries his parents. It worries his parents that he has disappeared. It is not likely that he can win the lottery. It is a big surprise that he is still alive. 3. 由连接代词、连接副词或whether引导的从句。 When she will be back is still a question. Where they had put the files troubled the spy. Whether he will take part in the play is unclear. Whether or not he will go to Japan is up to her. 主语从句的连接词----详述