主语从句超全
主语从句知识点总结文档
主语从句知识点总结文档一、主语从句的基本语法结构主语从句一般由连词that来引导。
引导词that不作其他任何成分，所以that很容易被忽略。
但有些从句可以用whether来引导，意思和that引导的主语从句相同。
从句的谓语用陈述语序，即“主语＋谓语＋宾语”的顺序。
例如：1. That he will come to see us is certain.（他会来看我们，是肯定的。
）2. That you can be happy is certain.（你能够幸福，是肯定的。
）3. Whether he will come to see us is uncertain.（他是否会来看我们，是不确定的。
）现在，让我们来详细介绍主语从句的用法。
二、主语从句的用法1. 主语从句在句中作主语，句子的谓语动词单数或者复数形式由主语从句的内容决定，因此主语从句的内容可以看作整个句子的主语。
例如：（1）What he said was true.他说的是真的。
（2）That he can speak Chinese is a fact.他会说汉语是一个事实。
（3）Whether she will come to the party is still unknown.她会不会来参加派对还不确定。
2. 主语从句的语序不可颠倒，即主语从句的语序是“引导词+主语从句”，而不是“主语从句+引导词”。
例如：（1）That he doesn’t like the movie is certain.（正确）He doesn’t like the movie is certain that.（错误）3. 在口语中，可以省略关系词that，但在书面语中，尽量不省略。
例如：He said he would come.（口语）He said that he would come.（书面语）4. 主语从句中的谓语动词要用陈述语序。
例如：（1）Why he did it is still unknown.（正确）Why did he do it is still unknown.（错误）5. 主语从句的从句中如果有主语和谓语，则主语放在谓语前。
(完整word版)主语从句讲解
主语从句1．定义：用作主语的从句叫做主语从句。
2．引导主语从句的关联词有三类：（1）从属连词that、whether。
如：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.Whether he’ll come here isn’t clear。
他是否会来这里还不清楚。
从属连词：that， whether等.that 引导主语从句只起引导作用,本身无实际意义，在主语从句中不充当任何成分，但不能省略.由whether及其他连词引导的主语从句放在句首，句后都可. If只能放在句中.造句:1。
、很明显他是个好人.2。
、他通过了考试让妈妈很高兴。
3、天气是否会转晴还不确定。
(3）（特殊疑问词）连接代词who, whom， whose， what, which, whoever， whatever, whichever 如：__________watch was lost is unknown.__________she did is not yet known. 她干了什么尚不清楚.__________side will win is not clear。
__________comes is welcome。
不论谁来都欢迎。
__________ was said has left us much to think。
这里说的话都应当保密.造句：1. 我们需要的是时间。
2。
谁将成为我们的班长还没有决定。
3。
哪本书更好还不知道。
(4) （特殊疑问词）连接副词 where, when, how， why，wherever，whenever，however。
___________ he did it remains a mystery.When they will start is not known yet.How this happened is not clear to anyone。
(完整版)主语从句详解+例句
(完整版)主语从句详解+例句主语从句是复合句中的一个重要成分，由一个从句作为主语，起到句子中主语的作用。
本文将详细介绍主语从句的结构和用法，并提供一些例句进行说明。
1. 主语从句的结构主语从句由引导词和一个从句组成，引导词在句子中充当主语的角色。
常见的引导词有：- that- whether/if- who- whom- which- what- whoever- whatever主语从句的结构可以是以下几种形式：- 陈述句形式：[that + 陈述句]- 一般疑问句形式：[whether/if + 陈述句]- 特殊疑问句形式：[疑问词 + 陈述句]2. 主语从句的用法- 主语从句可以替代主句中的名词或名词短语作为主语，使句子更加简洁明了。
例如：- That he is late is unacceptable.（他迟到是不能接受的。
）- What you said surprised me.（你说的话让我很吃惊。
）- 主语从句常用于强调句型中，强调句型的结构为：[It + 系动词 + 主语从句 + 其他成分]。
例如：- It is important that we take action now.（我们现在采取行动是很重要的。
）- It doesn't matter what they think.（他们怎么想并不重要。
）3. 主语从句的例句- That he didn't show up was disappointing.（他没有露面是令人失望的。
）- Whether she will join us is still unknown.（她是否会加入我们还不知道。
）- Who will be the winner is yet to be determined.（谁将会是胜利者还有待确定。
）- It is surprising that they didn't invite him.（他们没有邀请他是令人惊讶的。
(完整版)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）附属连词指引的主语从句（ that whether if）that 指引的主语从句 :指引词 that 无含义 /在句中不做成分 /不可以够省。
That 指引主语从句往常用it 作形式主语。
比如： That you will win the medal seems unlikely.That she survived the accident is a miracle.whether指引的主语从句:whether有含义(能否 )/ 在句中不做成分/不可以够省。
注意：指引主语从句，不可以用if 不可以在开头，只好用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）用连结代词指引的主语从句在由连结代词who, whose, whom, which, what, whoever, whomever, whichever, whatever指引的名词性从句中，其连结代词在句中起名词性作用，担当必定成分.比如： 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。
它指引主语从句，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 指引的退步状语从句的差别。
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. （退步状语从句）（＝ No matter who breaks the law, he should be punished.）（3）用连结副词 when, where, why, how 指引的名词性从句 (其连结副词有含义 ,在句中作状语。
英语 主语从句
英语主语从句1. What he said is true. 他说的是真的。
2. That she is coming to the party is certain. 她来参加聚会是肯定的。
3. Whether he will come is not known. 他是否会来还不知道。
4. Whoever comes will be welcome. 无论谁来都会受到欢迎。
5. Wherever you go, I will follow you. 无论你去哪里，我都会跟着你。
6. When he will come is a mystery. 他什么时候来是个谜。
7. Why he left is not clear. 他为什么离开还不清楚。
8. How she learned English is a mystery. 她是怎么学英语的是个谜。
9. It is certain that he will win the game. 他肯定会赢得比赛。
10. It is possible that he will come. 他有可能会来。
11. It is obvious that she is lying. 很明显她在撒谎。
12. It is important that you should tell the truth. 你说实话很重要。
13. It is necessary that he should study hard. 他努力学习是必要的。
14. It is strange that he should say so. 他居然这么说，真是奇怪。
15. It is a pity that he can't come. 他不能来，真是遗憾。
16. It seems that he is happy. 他似乎很快乐。
17. It happens that I know him. 我碰巧认识他。
主语从句ppt课件
选择题练习
要点一
总结词
理解主语从句的引导词和连接词
要点二
详细描述
提供一系列选择题，让学生根据句子语境和语法规则选择 正确的引导词和连接词，以理解主语从句的构成。
阅读理解练习
总结词
运用主语从句理解文章
详细描述
选取包含主语从句的短文或段落，让学生通 过阅读理解文章大意，并能够根据上下文推 断出主语从句所表达的含义。同时，可以要 求学生自己尝试构造主语从句来表达文章主 题或观点。
主语从句的分类
名词性从句
根据主语从句在句子中的作用和位置，可 以分为三类：名词性从句、形容词性从句 和副词性从句。
如句子“who is the president of the United States？”中的“who”引导的从 句就是名词性从句。
形容词性从句
副词性从句
如句子“what he said was interesting” 中的“what he said”是形容词性从句， 它修饰了形容词“interesting”。
主语从句的构成
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主语从句的构成
主语从句由引导词、主语 和谓语构成。
引导词
通常使用what、who、 whose、which等词来引 导主语从句。
例子
句子“what he said is true”中，“what”是引 导词，“he said”是主语 ，“is true”是谓语。
主语从句的分类
过去时态
如果主句使用过去时态，主语从句 也使用过去时态。
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主语从句的特殊用法
先行词在从句中担任的成分
先行词在从句中担任主语
当先行词在从句中担任主语时，从句的结构通常为主语+谓语+其他成分。
主语从句知识点归纳总结
主语从句知识点归纳总结一、主语从句的引导词主语从句的引导词有两种情况，一种是以“疑问词”引导的主语从句，如 what, which, who, whom, whose, where, when, why, how；另一种是以“that” 引导的主语从句。
在口语中也可以用 whether 引导主语从句。
这两者的使用没有根本的区别。
二、主语从句的位置主语从句通常位于谓语动词之后，而在连接动词和宾语之间，有时还可用于某些固定句型的主语位置，如“It is+名词/形容词+that/who/whether…”，“There be 句型”等。
在复杂句中，主语从句通常位于主句之前三、主语从句需要注意的语法规则1. 主语从句在句中充当主语成分，主要用来说明主要动作的主体。
如：What he said is true.（他所说的是真的。
）2. 主语从句的谓语动词形式一般要和主句之间的逻辑关系保持一致，即主语从句的谓语动词的数和人称要和主句之间的主谓一致。
如：What he says is true.（他所说的是真的。
）3. 主语从句的谓语动词通常用单数形式，如其中的谓语动词用于表示整体和抽象概念的名词作主语。
表示数量的概念的名词作主语时，谓语动词用复数形式。
如：What she told me was very important.（她告诉我的事情很重要。
）4. 当主语从句中表示的内容是一个具体的个体时，“Who”引导的主语从句谓语动词的单复数形式要和先行词一致。
“Who”引导的主语从句用单数形式表示组织或公司时，谓语动词用单数形式。
表示具体的公司或组织名词作主语时，谓语动词要用单数形式。
如：The girl who is standing over there is my friend.（站在那边的那个女孩儿是我的朋友。
）The team that is winning a prize is from Beijing. （获奖的那个队是北京队。
主语从句超全ppt课件
第二讲：主语从句的引导词及各 类主语从句
主语从句在复合句中作句子的主语。 引导主语从句的词有从属连词that, whether, if；连接代词who, whoever, whom, what, whatever, whose, which； 连接副词when, where, how, why等。
surprise/no wonder难怪/good news/a good thing/a question /that… …是事实
It is common knowledge that… …是常识
*_It__is__a__p_it_y__th__a_t_(很遗憾)we lost the match.
句子
简单句 复合句
并列句
形容词性从句 名词性从句 副词性从句
定语从句
主语从句 subject clause
宾语从句 object clause
表语从句 predicative clause
同位语从句 appositive clause
比较状语从句 地点状语从句 时间状语从句 让步状语从句 条件状语从句 目的状语从句 方式状语从句 结果状语从句 原因状语从句
*____I_t _is_r_e_p_o_rt_ed__th_a_t_(据报道)20 people were killed in the accident.
*___It_i_s_s_u_g_g_es_t_e_d_th_a_t__(建议)we should eat more vegetable and do more exercise.
特殊疑问句作主语
• 需要先将疑问句的倒装语序变成陈述句语 序。
Why dinosaurs became extinct is still a mystery.
主语从句全
the man wearing a dress he won the competition a hurricane will arrive soon everyone can be the champion
It is necessary that…
one should obey the law
It is strange that…
2. That there is no dental caries (没有蛀牙) is our common goal.
由that引导的主语从句
That 引导的主语从句放在句末 用it 作形式主语放在句首
1.It has been known for years that Mount Qomolangma is the highest mountain in the world. 2.It is obvious that he is a workaholic. 3.It is a fact that the world is round.
一个众所周知的事实是，一个单身汉若是非常有钱，句
句型三： It + be + 名词短语 + that从句
名词短语中的一部分名词与同位语从句中的先行词相同
翻译：1.鲸鱼不是鱼类，这是一个常识。 It is common knowledge that the whale is not a fish. 2.巴西没有赢得比赛，真是太可惜了。
由that引导的主语从句
句型一： It + be + 过去分词 + that 从句
It is reported that… It is believed that… It has been found that…
超详细主语从句(精华版)
主语从句：做主语用的名词性从句，因其在复合句中做主语，又称主语从句，引导主语从句的有从属连词that ，w hether，连接代词who ，what ，which ，连接副词when，where，how，why 等；1.从属连词：that，whether 等.that 引导主语从句只起引导作用，本身无实际意义，在主语从句中不充当任何成分，但不能省略；That he will win is certain. 他确定会赢；Whether he’ll come here isn’t clear. 他是否会来这里仍不清晰；留意: 由that 引导的主语从句有时为了使句子结构平稳, 防止“头重脚轻”, 常用it 作形式主语, 而把从句放在后面；例如: 1. That he will refuse this piece of advice is impossible.It is impossible that he will refuse this piece of advice.2.That they should like each other is natural.这样就构成了下面一些常用句型:1) It is + n. + 从句It is a pity/shame that... 遗憾的是⋯⋯Itis a surprise that⋯令人诧异的是⋯It isa fact that⋯⋯是事实It is common knowledge that ⋯⋯是常识2) It is + adj. + 从句It ’s certain that⋯肯定⋯Itis possible that... 很可能⋯⋯It isunlikely that... 不行能⋯⋯It isobvious that ⋯很明显⋯It is necessary \important \natural\strange... that⋯3) It + 不及物动词+从句It happened that... 碰巧⋯⋯Itoccurred to me that⋯我突然想起⋯Itstruck/hit sb. that⋯4) It + be +过去分词+从句It is said that... 据说⋯⋯Itis known to all that... 众所周知⋯⋯It isreported that... 据报道⋯⋯It is believed that...据信⋯⋯;人们信任⋯⋯It issuggested that + (should）do... 建议⋯⋯It cannot be denied that⋯不行否认⋯⋯deny2. 连接代词who ，what ，which, whatever, whichever, whoever (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)What many scientists believe is that the earth is round ⋯Who will take part in the meeting has not been decided. Whoever breaks the law will be punished.3. 连接副词when，where，how，why 等；Why they suddenly disappeared still remains a mystery.When they will leave is not decided.Where she is from is unknown.How we will paint the house has not been decided.主语从句的规律：规律一，主语从句一律用陈述语序，即主语在前，谓语在后；When he will come is not known.规律二，连词that 在从句中无实际意义，但不能省略；That he will not come to the meeting this evening is true.规律三，whether 可以引导主语从句，放在句首，但if 不能Whether the meeting will be put off has not been decided yet.规律四，主语从句中的连词不能重叠使用；That he will help others is a fact.规律五，含主语从句的主句谓语动词多用单数第三人称形式；When he will come are a puzzle.When he will come is a puzzle.规律六，what 引导的主语从句，可依据表语打算主句动词的单复数形式；What he needs is that book.What he needs are some books.规律七，主语从句为了防止头重脚轻现象，用it 做形式主语，而把从句放在后面；That the earth turns around the sun is known to all.It is known to all that the earth turns around the sun.。
高中英语语法-主语从句(共22张PPT)
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When he will be back depends on the weather. Where the test will be given is not yet decided. Where and when he was born is a secret. Why he came here is not known. How we can protect the endangered animals
turning white.
√ A. while B. that
C. if
D. for
5._______ he said at the meeting shocked
everybody present.
√A. What B. That C. The fact D. The matter
6._________ we can't get seems better than
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四、it 可作形式主语
为了使句子保持平衡，避免头重脚轻,经常用 it 作形式 主语,主语从句放在后面作真正的主语. 其结构为：
It + 谓语动词/系动词 + 宾语/表语 + 主语从句. 例如:
That we shall be late is certain. = It is certain that we shall be late. 1. That the earth is round is known to all. = It is known to all that the earth is round. 2. whether they would support us was a problem . = It was a problem whether they would support10us.
(完整版)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 matt er 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 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 hasn’t been 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.(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 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.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.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; astonishing, 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 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 pro ved 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.D. It seems（happened / appears / doesn’t 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 missed 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 estimateB. The estimatedC. They are estimatedD. It is estimated that2. _____ some mammals came to live in the sea is not known.A. WhichB. SinceC. AlthoughD. How3. _____ we have achieved is attributed to the guidance of our parents.A. WhoeverB. WhateverC. HoweverD. That4. _____ wealthy does not necessarily mean that a man is greedy.A. For the reason that he isB. Just because he isC. The reason of beingD. That he is5. Although ___ happened in this developed country sounds like science fiction, it could occur elsewhere in the world.A. whichB. whatC. howD. it6. _____ she had forgotten to take her notebook.A. That occurred to herB. She occurred thatC. To her that occurredD. It occurred to her that7. I am sure that _____ she said is wrong.A. whichB. allC. thisD. what8. We lost our way in the forest, and ____ made matters worse was that it was getting dark.A. thatB. whichC. itD. What9. _____ or not is still uncertain.A. He’s comingB. If he is comingC. That comingD. Whether he’s coming10. It’s _____ he’ll be able to come.A. doubt whetherB. doubtfulC. doubt itD. doubtful whether11. ______ he is at work in the heart of the big city or at home in the quiet suburb, Dick’s l ife is tied to machines.A. WhetherB. TillC. IfD. Unless12. _____ he saw both surprised and frightened him.A. ThatB. WhenC. WhatD. Which13. _____ is warm sunshine.A. What do we all need.B. What all we needC. What we needD. What we all need14. _____ is a pity that he should feel so upset.A. WhatB. ThatC. HeD. It15. _____ a spoonful of soil can tell us so much about the structure and early history of the moon.A. RemarkableB. Quite remarkablyC. It is remarkable thatD. It is remarkable fact that16. _____ you nominate will be elected.A. WhoB. WhomC. WhomeverD. That’s17. _____ book you borrow must be returned within a week.A. WhatB. WhichC. WhicheverD. That’s18. _____ of us gets home first starts cooking.A. WhoB. WhichC. WhicheverD. Anyone1.________ makes mistakes must correct them.A. WhatB. ThatC. WhoeverD. Whatever2. It worried her a bit ____ her hair was turning grey.A. whileB. thatC. ifD. for3.When and why he came here ________ yet.A. is not knownB. are not knownC. has not knownD. have not known4. ________ 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 lateD. Being a few minutes late5. ________ Tom liked to eat was different from ________.A. That…that you had expectedB. What …that you had expectedC. That…what you had expectedD. What…what you had expected6.________ we go swimming every day ________ us a lot of good.A. If...doB. That...doC. If...doesD. That...does7.It ________ Bob drives badly.A. thinks thatB. is thought whatC. thought thatD. is thought that8.It's uncertain ________ the experiment is worth doing.A. ifB. thatC. whetherD. how9.________ the boy didn't take medicine made his mother angry.A. ThatB. WhatC. HowD. Which10.____ we can't get seems better than ____ we have.A. What, whatB. What, thatC. That, thatD. That, what11.____ you don't like him is none of my business.A. WhatB. WhoC. ThatD. Whether12..____ we'll go camping tomorrow depends on the weather.A. IfB. WhetherC. ThatD. Where13._________is going to do the job will be decided by the Party committee.A. ThatB. WhyC. HowD. Who14._______we'll finish translating the book depends on the time.A. WhenB. WhyC. WhatD. That15.______he won't go there is clear to all of us.A. HowB. WhatC. WhyD. This16.______the house will be built will be discussed at tomorrow's meeting.A. IfB. WhereC. ThatD. What17._______you come or not is up to you.A. WhatB. IfC. WhyD. Whether18._______makes mistakes must correct them.A. WhoB. AnyoneC. WhoeverD. Anybody19._______team will win the match is a matter of public concern.A. WhichB. ThatC. IfD. How20. Who is this factory __________ some foreign friends visited last Friday?A. thatB. whereC. whichD. the one21.Is this factory you visited the other day?A. thatB. whereC. in whichD. the one22.________leaves the room last ought to turn off the lights.A. AnyoneB. The personC. WhoeverD.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 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. What she couldn’t understand was that fewer and fewer students showed interest in her l essons. 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 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 see ms 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: 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 /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 is ____ we sleep because our brain is “programmed” to make us do so.A. whenB. whyC. whetherD. 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. whyB. whereC. whatD. 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“where 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. whyB. whenC. whatD. 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 couldn’t understand was ____ fewer and fewer students showed interest in her lessons.A. What; whyB. That; whatC. What; becauseD. 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 students had been admitted to key universities.A. What; becauseB. What; thatC. That; whatD. 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 yesterday’s game?—Oh, that’s ____.A. what makes me feel excitedB. whatever I feel excited aboutC. how I feel about itD. 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①语序: 从句的语序必须是陈述句语序, 即“主语+ 谓语”这种形式.②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).③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 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. ifC. whenD. whether 2．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 there 4．The problem is _________to take the place of TedA. who can we getB. what we can getC. who we can getD. that we can 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 come is ___________.A. because his mother is illB. because of his mother’s being illC. that his mother is illD. for his mother is ill11. —He was born here.-- That is _______ he likes the place so much.A. thatB. whatC. whyD. how12.That is ______ Lu Xun once lived.A. whatB. whereC. thatD. Why二1．_______your father wants to know is________ getting on with your studies.A. What; how are youB. That；how you areC. How；that you areD. What；how you are2. The trouble is__________we are short of tools.A. whatB. thatC. howD. why that3. America was __________was first called “India” by Columbus.A. whatB. whereC. the placeD. there where4. China is becoming stronger and stronger. It is no longer_________ .A. what it used to beB. what it was used to beingC. what it used to beingD. what it was used to be5. ________he really means is ________he disagrees with us.A. What … thatB. That … whatC. What … whatD. That … what6. The energy is ________ makes the cells able to do their work.A. thatB. whichC. whatD. 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. where2. I had neither a raincoat nor an umbrella ____I got wet through.A. It’s the reasonB. That’s whyC. There’s whyD. It’s how3. See the flags on top of the building? That was ______ we did this morning.A. whenB. whichC. whereD. what4. --- Are you still thinking about yesterday’s game?---Oh, that’s _____.A. what makes me feel excitedB. whatever I feel excited aboutC. how I feel about itD. when I feel excited5. What surprised me was not what he said but ______ he said it.A. the wayB. in the way thatC. in the wayD. the way which1.The question is ________ we will have our sports meet next week.A. thatB. ifC. whenD. whether 2．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 there 4．The problem is _________to take the place of TedA. who can we getB. what we can getC. who we can getD. that we can 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 come is ___________.A. because his mother is illB. because of his mother’s being illC. that his mother is illD. for his mother is ill11. —He was born here.-- That is _______ he likes the place so much.A. thatB. whatC. whyD. how12.That is ______ Lu Xun once lived.A. whatB. whereC. thatD. why 13．_______your father wants to know is________ getting on with your studies.A. What; how are youB. That；how you areC. How；that you areD. What；how you are14. The trouble is__________ we are short of tools.A. whatB. thatC. howD. why that15. America was __________was first called “India” by Columbus.A. whatB. whereC. the placeD. there where16. China is becoming stronger and stronger. It is no longer_________ .A. what it used to beB. what it was used to beingC. what it used to beingD. what it was used to be17. ________he really means is ________he disagrees with us.A. What … thatB. That … whatC. What … whatD. That … what18. The energy is ________ makes the cells able to do their work.A. thatB. whichC. whatD. such19 —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. where20 .I had neither a raincoat nor an umbrella ____I got wet through.A. It’s the reasonB. That’s whyC. There’s whyD. It’s how21. See the flags on top of the building? That was ______ we did this morning.A. whenB. whichC. whereD. what22. --- Are you still thinking about yesterday’s game?---Oh, that’s _____.A. what makes me feel excitedB. whatever I feel excited aboutC. how I feel about itD. when I feel excited23. What surprised me was not what he said but ______ he said it.A. the wayB. in the way thatC. in the wayD. the way which综合练习1. It has been proved _________ eating vegetables in childhood helps to protect you against serious illnesses in later life.A. ifB. becauseC. whenD. that2. The last time we had great fun was ________ we were visiting the Water Park.A. whereB. howC. whenD. why3. ________ matters most in learning English is enough practice.A. WhatB. WhyC. WhereD. Which4. The traditional view is ______ we sleep because our brain is “programmed” to make use do so.A. whenB. whyC. whetherD. that5. ______ parents say and do has a life-long effect on their children.A. ThatB. WhichC. WhatD. As6.________ is our belief that improvements in health care will lead to a stronger, more prosperous economy.A. AsB. ThatC. ThisD. It7. ______ team wins on Saturday will go through to the national championships.A. No matter whatB. No matter whichC. WhateverD. Whichever8. You are saying that everyone should be equal, and this is ______ I disagree.A. whyB. whereC. what .D how9. After Yang Liwei succeeded in circling the earth, ____ our astronauts desire to do is walk in space.A. whereB. whatC. thatD. how10. I think Father would like to know ______ I’ve been up to so far, so I decide to send him a quick note.A. whichB. whyC. whatD. how11. Our country is developing at an amazing speed, and this is ______ makes me feel so proud.A. whatB. whichC. thatD. why12. ________ puzzles the scientists how these creatures can survive in such severe conditions.A. WhatB. AsC. ThatD. It13. _____ leaves the room last ought to turn off the lights.A. AnyoneB. WhoC. WhoeverD. The person14. Inside the White House, there is a room called the Oval Office. That’s _______ the president works.A. wheyB. whenC. whatD. where15. ______ you will be admitted to York University will be decided by the Admission Committee.A. ThatB. WhetherC. WhatD. If16. The reason ____ I plan to go is _____ she will be disappointed if I don’t.A. why; thatB. that; becauseC. which; becauseD. why; for17. We sell handmade gifts. _____gift you order from us is unique for the special person!A. WhichB. ThatC. WhicheverD. What。
主语从句超全练习题及答案
主语从句超全练习题及答案主语从句练题I.用适当的词填空，使句子意思完整。
1.Why XXX.2.The Foreign Minister said,“It is our hope that the two sides will work towards peace.”3.Which team will win the match is still unknown.4.XXX to the party will receive a present.5.Whether Mary has left is still a n.6.It’XXX.7.XXX us.8.We usually think what we can’t get seems better than what we have.9.It is a fact that English is being accepted as an nal language.10.Who is to be sent there to solve the problem hasn’t been decided.II.下列各句中均有一处错误，请改正。
1.What the old man’s son wanted to know was where the gold had been hidden.2.It XXX.3.XXX his task on time is of great importance.4.Whether the 2008 Olympic Games will be held in Beijing XXX(改为：That the 2008 Olympic Games will be held in Beijing XXX.)5.XXX。
XXX is to walk in space.6.The last person leaving the room should turn off the lights.7.The reason why they will solve the us problem today has not been decided yet.8.It is still XXX.9.It is currently unknown whether our spring sports meet will be held this week or not.10.It'XXX.主语从句研究指导：1.That the earth travels round the sun is a well-known fact.2.It is uncertain whether the artist can do it or not.3.Who will play the lead in the play has not been decided yet.4.Where the young man has gone is not known.5.When and where the test will be given is not yet decided.常见错误展示：1.It is common knowledge that light travels XXX.2.XXX.3.What the professor said is of great importance.4.Where the trees will be planted has not been decided。
（完整）高中英语主语从句全面讲解
（完整）高中英语主语从句全面讲解语法——Noun clauses as the subject主语从句如果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。
①That he finished writing the composition in such a short time surprised us all.②What we need are good doctors.③Whom we must study for is a question of great importance.1.主语从句的连接词1).连接词: that, whether①.That he will win is certain.②.Whether he’ll join us in the discussion is of great importance.2).连接代词: who, what, which, whom , whose, whoever, whatever, whichever①.It is clear who is afraid of having a change in land ownership.②.What India needs is a law to make land ownership fairer.3).连接副词: when, where, why, how, how many, how much , how long, how soon, how often①When we’ll start tomorrow wil l be told soon.②Where we can buy oxen is something we need to find out.③Why he came here is not known.④How we can protect the grain from damp needs to be discussed.【连接词】1. that——That t he earth moves around the sun is well known.2. whether——Whether he will come or not is not known yet.3. who ——Who will be sent there has not been decided.4. what——What you need is more practice.5. which——Which one is the best is not clear.6. when, where ——Where he has gone is a question.7. why, how——Why there is gravity is hard to understand.How he can earn a living in Britain remains a big problem.8. whoever、whatever、whichever可引导主语从句。
主语语从句知识点总结
主语语从句知识点总结名词性从句：名词性从句是一类特殊的从句，它在句子中充当名词的作用。
名词性从句包括：主语从句、宾语从句、表语从句和同位语从句。
主语从句是其中的一种，以下是主语从句的知识点总结。
一、主语从句的基本结构主语从句的基本结构是“连接词+主语从句”，“连接词”一般是连词that、whether或者特殊疑问词（what, who, which, where, when, how等）。
1. 连词thatthat引导的从句在口语中常省略，仅在从句谓语动词有一些不同时才需要保留。
例如：It is clear that she is a hardworking student.（她是一个用功的学生是清楚的。
）2. 连词whetherwhether表示“是否”的意思。
用whether引导的主语从句，一般用于宾语介词后。
例如：The question is whether we should continue to support them.（问题是我们是否应该继续支持他们。
）3. 特殊疑问词特殊疑问词用来引导疑问句，也可以用来引导主语从句。
例如：What she said is not important.（她说的不重要。
）二、主语从句的用法主语从句可以在句子中充当主语，通常出现在表述事实、真理、信仰、愿望等抽象概念的句子里。
1. 表述事实例如：That he is always late is well known.（他总是迟到是众所周知的。
）2. 表述真理例如：That honesty is the best policy cannot be denied.（诚实是最好的政策是无可否认的。
）3. 表述信仰例如：What he said is beyond my belief.（他说的超出了我的想象。
）4. 表述愿望例如：That you will come to my party makes me happy.（你能来参加我的聚会让我很高兴。
主语从句超全练习试题和答案解析
主语从句练习题[即学即用]I. 用适当的词填空，使句子意思完整。
1. ______ he didn’t attend the meeting yesterday wasn’t quite clear.2. The Foreign Minister said, “It is our hope ______ the two sides will work towards peace.”3. ______ team will win the match is still unknown.4. ______ comes to the party will receive a present.5. ______ Mary has left is still a question.6. It’s reported ______ three people were killed in the accident and five were hurt badly.7. ______ he solved the problem successfully interested all of us.8. We usually think ______ we can’t get seems better than what we have.9. It is a fact ______ English is being accepted as an international language.10. ______ is to be sent there to solve the problem hasn’t been decided. II. 下列各句中均有一处错误，请改正。
1. That the old man’s son wanted to know was where the gold had been hidden.2. It is reported when China has successfully sent Shenzhou VI spaceship into space.3. If he can finish his task on time is of great importance.4. Whether the 2008 Olympic Games will be held in Beijing excited the whole nation.5. After Yang Liwei succeeded in circling the earth, which our astronauts desire to do is walk in space.6. Whatever leaves the room last ought to turn off the lights.7. Why they will solve the serious problem today has not been decided.8. When will win the English competition is still a problem.9. How our spring sports meet will be held or not this week is not known yet.10. It’s strange when he should have gone away without telling us. GRAMMAR主语从句学习指导[寻规找矩] 请观察下列句子，注意主语从句的用法。
主语从句语法详解
主语从句语法详解在英语中，主语从句是非常重要的一个语法知识，主语从句涉及的知识也非常多，需要我们耐心去理解，要不然容易混淆。
下面是小编给大家带来的英语语法主语从句_主语从句语法详解，以供大家参考，我们一起来看看吧!主语从句在复合句中作主句的主语,引导主语从句的词有从属连词 that, whether 以及连接代词 who, what,which, whoever, whatever, whichever 和连接副词 when, where, why, how 等.例如:That she was chosen made us very happy.她当选了使我们很高兴.What caused the accident is a completemystery.是什么导致了这次事故还完全是一个谜.Whether she will come or not is still a question.她是否来还是一个问题.Which team will win the match is stillunknown.哪个队会赢得这场比赛还不知道.Whoever comes to the party will receive apresent.参加聚会的每一个人都将收到一份礼物.When they will start has not been decidedyet.他们何时出发还没决定.注意:上述例句中的主语从句都是放在句首,但有时为了使句子结构平衡,避免"头重脚轻",常用 it 作形式主语,而把从句放在后面.例如:It is a pity that she has made such amistake.她犯了这样一个错误,真是遗憾.It depends on the climate whether they aregoing shopping today.他们是否今天去购物还得看天气情况.这样就构成了下面一些常用句型:1)It is + adj. / n. +从句It is a pity/shame that...遗憾的是……It is possible that...很可能……It is unlikely that...不可能……2)It +不及物动词+从句It seems/appears that...似乎……It happened that...碰巧……3)It + be +过去分词+从句It is said that...据说……It is known to all that...众所周知……It is reported that...据报道……It is believed that...据信……;人们相信……It is suggested that...有人建议……It must be pointed out that...必须指出……It has been proved that...已证明…….例如:It is believed that at least a score ofbuildings were damaged or destroyed.据信,至少有二十座楼房遭到破坏或彻底毁掉.It is suggested that the meeting should beput off.有人建议会议延期召开.It's reported that three people were killedin the accident and five were hurt badly.据报道,事故中三人丧生,五人重伤.It is known to all that Taiwan is aninseparable part of China.众所周知,台湾是中国不可分割的一部分.<例句>It's certain that prices will go up.物价肯定要上涨的。
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主语从句 (Subject Clause)
第一讲:主语从句的概念，什么是主语从
句。在句子中充当主语的就是主语从句。
英语名词从句成分的划分是根据句子在从句中的 位置划分的，任何一个句子一旦位于某个成分的 位置上，它就成了相应的 ......语从句
如何理解主语从句
他通过了考试让老师很高兴。
He passed the exam. It made the teacher happy. He passed the exam made the teacher
happy. That he passed the exam made the teacher happy.
理解主语从句
他何时要来还不清楚。 When will he come? It is not clear. When will he come is not clear.
When he will come is not clear.
第二讲：主语从句的引导词及各 类主语从句
主语从句在复合句中作句子的主语。 引导主语从句的词有从属连词that, whether, if；连接代词who, whoever, whom, what, whatever, whose, which； 连接副词when, where, how, why等。
*it为形式主语
2.That they should like each other is natural. _I_t _is__n_a_tu__ra_l_t_h_a_t_t_h_e_y_s_h_o_u__ld__li_k_e_e_a_c_h__o_th__er.
这样就构成了下面一些常用句型:
1) It is /系动词+ n. +从句 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/ a problem/a wonder/an honner/a
It is believed that...据信……;人们相信……
It is suggested that + (should）do... 建议……
It must be admitted that…必须承认……
It cannot be denied that… 不可否认……
It must be pointed out that…需指出的是……
主语从句的结构：句子+谓语 连接词所连接的句子是从句，从句和之后的谓语 构成主句。
主语从句+谓语 主语从句的句序：
it（形主）+that（真主）
充当主语的句子
• 陈述句 （用that引导） • 一般疑问句 （用whether引导） • 特殊疑问句 （用when, where, why, how,
has not been decided. 该句中主语从句是 _W__h_e_t_h_e_r_w__e_w_i_l_l __ _tr_a_v_e_l_a_b_r_o_a_d__o_r_n_o_t_，引导词为 _w_h__et_h_e_r__。
4. Whoever knows the secret mustn’t tell
effective.
3) It +不及物动词+从句
It happened that...
碰巧……
It occurred to me that…我突然想起…
*_I_t_h_a_p_p_e_n_e_d__t_h_a_t_(刚好)I came into the office at that time.
*_I_t _o_c_c_u_r_re_d__t_o_m__e_t_h_a_t_(我突然想起)I forget to sent the letter.
that… +(should) +do…
这类主语从句中，谓语动词很多为（should )+动词原形
*_I_t_is__p_o_s_s_i_b_le__th_a_t__(很可能)she will come back tomorrow. *__It_i_s_o__b_v_io_u_s__th__a_t _(很明显)this measure is
*____I_t _is_r_e_p_o_rt_ed__th_a_t_(据报道)20 people were killed in the accident.
*___It_i_s_s_u_g_g_es_t_e_d_th_a_t__(建议)we should eat more vegetable and do more exercise.
2）.It + be +过去分词+从句 3）.It doesn't matter how/weather......结构中的主语从句 不可提前。
4）it+特殊动词+that 从句常用于这种特殊结构的动词； seem,appear显得，happen碰巧/doesn't matter/make no difference/occured 主语从句不可提前。 5）含主语从句的复合结构是疑问句时，主语从句不可提前。
什么是主语
I like English. The train left.
主语：句子说明的人或事物,一般 位于_句__首___ 。
找出主语
Jane is good at playing the piano.(名词) To see is to believe. （不定式） Smoking is bad for health. （动名词） What he has said is true. (从句）
Noun clauses as the subject
句子
简单句 复合句
并列句
形容词性从句 名词性从句 副词性从句
定语从句
主语从句 subject clause
宾语从句 object clause
表语从句 predicative clause
同位语从句 appositive clause
比较状语从句 地点状语从句 时间状语从句 让步状语从句 条件状语从句 目的状语从句 方式状语从句 结果状语从句 原因状语从句
known/estimated/expected/hoped//notedБайду номын сангаасrequired/demanded/made
clear/discussed/
It is said that...
据说……
It is known to all that... 众所周知……
It is reported that... 据报道……
5）.it+特殊动词+that 从句常用 于这种特殊结构的动词； seem,appear显得，happen碰 巧/doesn't matter/make no difference/occured 主语从句不 可提前。
.2.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距于复合句句首
That he will come is certain.
1. 主语从句有时为了使句子结构平衡, 避免 “头重
脚轻”, 常用 it 作形式主语, 而把从句放在后面。
例如:
1. That he will refuse this piece of advice is impossible. __I_t _is__im__p_o_s_s_i_b_le__th_a_t_h__e_w_i_ll_r_e_f_u_s_e_t_h_i_s_p_i_e_c_e __o_f_a_d_v_i_c_e_._____________________________
特殊疑问句作主语
• 需要先将疑问句的倒装语序变成陈述句语 序。
Why dinosaurs became extinct is still a mystery.
Why did dinosaurs become extinct is still a mystery.
恐龙为什么会灭绝目前还是个未解之谜。
怎样找出主语从句以及主句和从句
That he will succeed is certain. Whether he will come makes no
difference. What we need is more time.
结论；判断主语从句的方法；先找到谓语，谓语 之前的句子就是主语从句。位置：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。
others. 该句中主语从句是_W__h_o_e_v_e_r__k_n_o_w_s__th_e_ _s_e_c_re_t_，引导词为__w_h_o_e_v_e_r。
5. It remains a puzzle why dinosaurs died
out suddenly long time ago. 该句中主语从句是_w__h_y_d_i_n_o_s_a_u_r_s_d_i_e_d o_u__t _s_u_d_d_e_n_ly__lo_n__g_t_im__e_a_g_o_，引导词为 _w_h_y__。
surprise/no wonder难怪/good news/a good thing/a question /that… …是事实
It is common knowledge that… …是常识
*_It__is__a__p_it_y__th__a_t_(很遗憾)we lost the match.
*I_t_i_s_a__f_a_c_t_t_h_a_t_(这是事实)he cheated in the exam.
2) It is /系动词+ adj. +从句 常见的形容词是
It’s certain that… 肯定… It is possible that... 很可能…… It is（ un）likely that... 不可能…… It is obvious that… 很明显… It is necessary \important \natural\clear/right/strange/true/good/wonderful/quite/unusual /evident/worthwhite/surprising/interesting/astonishing/doubtful/essential/...