高中语法系列之名词性从句
高中英语名词性从句知识讲解以及练习题 附答案
高中英语名词性从句知识讲解以及练习题附答案一、名词性从句概述名词性从句是一种充当名词作用的从句，通常在主句中作主语、宾语、表语或同位语。
它通常由引导词（如that, whether, if, who, whom, whose, which, what等）引导，并且从句中含有一个主语和谓语。
名词性从句的种类有很多，包括主语从句、宾语从句、表语从句和同位语从句等。
下面我们将逐一介绍这些从句。
二、主语从句主语从句作为一个名词，通常位于句首，是一个句子，主要作用是作为主句的主语。
引导主语从句的词：What (什么)；Whether (是否)；If (是否)；That (那个)。
例句：What he said is true. (他说的是真的。
)Whether it will rain tomorrow is uncertain. (明天是否会下雨还不确定。
)If you go, I will go too. (如果你走，我也跟着走。
)That he is coming is good news. (他来的消息是好消息。
)注意：主语从句的谓语动词通常要用单数形式。
What引导的主语从句通常用来表示“事物”的概念。
三、宾语从句宾语从句是一个名词，通常位于主句的动词后面，作为主句的宾语。
它可以由常见的宾语从句引导词引导，例如whether, if, that, who, whom, whose, what, when, where, how等。
引导宾语从句的词：Whether (是否)；If (是否)；That (那个)；Who (谁)；Whom (谁)；Whose (谁的)；What (什么)；When (何时)；Where (何处)；How (如何)。
例句：I know that he is coming. (我知道他要来。
)I wonder if he is telling the truth. (我想知道他是否说了真话。
高中语法之-名词性从句 S
名词性从句专题讲解一、复习句子成分二、句子种类简单句、并列句、复合句（三大从句）一、名词性从句：在句子中起名词作用的句子叫名词性从句(Noun Clauses）。
1）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。
2）因此根据它在句中不同的语法功能，名词性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。
主语从句What he wants to tell us is not clear.宾语从句He has told me that he will go to Shanghai tomorrow.名词性从句表语从句The fact is that we have lost the game.同位语从句I have no idea when he will come back home.1. 这里重点强调一下同位语从句，顾名思义，所谓同位语从句就是一个句子与主句中某一个名词互为同位语！那么什么是同位语呢，很简单就是相同地位，相同成分，平起平坐，A(名词)=B（从句）, B（从句）=A（名词）, 去掉任何一部分（A/B）对整个句子都不影响。
2. 而且与从句互为同位语的名词一般为抽象名词，例如：advice、demand、doubt、fact、hope、idea、information、message、news、order、problem、promise、question、request、suggestion、truth、wish、word等。
二、引导名词性从句的连接词1.引导名词性从句的连接词可分为三类：1.连词：that（无任何词意）whether, if（均表示“是否”）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2. 连接代词：what, whatever, who, whoever, whom, whose, whichever, whomever3. 连接副词：when, where, how, why, how many, how much, how often2. 连接词的判定：根据连接词在从句中所做的不同的成分，我们可以归纳如下：人物主语：who what宾语：whom what名词性从句表语：whom what定语：which what whose状语：when where why how (how many, how much, how often)不做成份：that if/whether as if /as though互动精讲【知识梳理1】宾语从句（一）宾语从句简介用作宾语的从句叫做宾语从句。
高考英语语法之名词性从句
1.名词：表示人或事物的名称的词叫名词。 2.名词的句法作用：名词在句中主要作主语、宾 语、表语和同位语。另外还可以作定语、状语。 3.名词性从句： 在英语的句子结构中，本来该由名词充当的主 语、宾语、表语和同位语，由一个句子来充当， 这个句子就叫名词性从句。 4.名词性从句的种类： 根据名词性从句在句子中所充当的不同成分， 名词性从句可以分为主语从句、宾语从句、表 语从句和同位语从句。
2.When he will go to America is not yet fixed.
(It is not yet fixed when he will go to America.)
宾语从句
在复合句中作主句的宾语.引导 词有连词that (that 常可省 略),whether,if; 代词有who, whose,what ,which
表语从句
在复合句中作主句的表语. 引导词有连词that (that 不可 省),whether; 代词有who, what ,which;
副词 when ,where, how, why
等.
The problem is that we didn’t get in touch with him.
This is how Henry solved the problem. His suggestion is that we (should) finish the work at once.
(4).It is not yet decided which cash crop will be produced next year. (5).Whatever he said was right.
(6).Whoever goes there must get ready by 6 o’clock.
高考英语语法名词性从句讲解及练习
语法复习之名词性从句名词性从句相当于名词，可分别作主句的主语、表语、宾语和同位语。
因此，名词性从句厅分为主语从句、表语从句、宾语从句和同位从句。
（一）引导名词性从句的连接词1、连接代词：who, whose, whom, what, which。
有词义，在从句中担任成分，如主语、表语、宾语、或定语等。
2、连接副词：when, where, why, how。
有词义，在从句中担任成分，作状语。
3、连接词：that, whether, if, as if。
that 无词义，在从句中不担任成分，有时可省略；if (whether), as if虽有词义，但在从句中不担任成分。
注意：连接代词与连接副词在句中不再是疑问句，因而从句中谓语不用疑问式。
连接代词与连接副词在从句充当句子成分，连接词whether 和if（是否），as if（好象）在从句中不充当句子成分，只起连接作用。
根据句义，如果连接代词与连接副词，whether、if 和as if都用不上时，才用that作连接词（that本身无任何含义）。
（二）主语从句1、主语从句在复合句作主语。
e.g. Who will go is not important.2、用it作形式主语，主语从句放在句末。
e.g. It doesn’t matter so much whether you will come or not.3、that引导主语从句时，不能省略。
e.g. That he suddenly fell ill last week made us surprised.（三）表语从句1、表语从句在复合句中作表语，位于系动词之后。
e.g. The question was who could go there.2、引导表语从句的连接词that有时可省去。
e.g. My idea is (that) we can get more comrades to help in the work.（四）宾语从句1、宾语从句在复合句中作宾语。
高考英语语法知识点：名词性从句
高考英语语法知识点：名词性从句1500字名词性从句是指在句子中充当名词的成分的从句。
名词性从句分为主语从句、宾语从句、表语从句和同位语从句。
在高考英语中，名词性从句是考查的重点之一，我们需要对名词性从句的结构和用法有透彻的理解。
下面是关于名词性从句的一些重要知识点：1.主语从句主语从句在句中充当主语的作用。
主语从句通常以that引导，也可以用whether或if 引导。
例如：- That he is guilty is certain.- Whether we will win the game is yet to be seen.- If it will rain tomorrow is still uncertain.2.宾语从句宾语从句在句中充当宾语的作用。
宾语从句通常以that引导，也可以用whether或if 引导。
需要注意的是，当主句的动词是说、tell、ask、think、believe、know等表示说话、思考、感觉的动词时，常用连词that引导宾语从句，但如果宾语从句的主语与主句的主语相同，可以省略连词that。
例如：- I know that he is a good student.- She asked me if/whether I had finished my homework.- He told her (that) he loved her.3.表语从句表语从句在句中充当表语的作用。
表语从句通常以that引导，也可以用whether或if 引导。
例如：- The fact that he didn't come is disappointing.- The question is whether we should proceed with the plan.- My concern is if/whether we have enough time.4.同位语从句同位语从句用来解释或说明前面名词的具体内容或意义。
高中英语语法名词性从句
规律一：名词性从句在句中要用陈述语序
II．引导词的选择
1. ____ we can't get seems better than ____ we
have. A.What , what C. That , that
B. What , that D. That , what
2. It worried her a bit ____ her hair was turning grey. A．while C．if B．that D．for
规律四：主语从句和宾语从句在适当的情况 下可以借助 “it” 而后置。
1.主语从句可以用it （作形式主语） 来替换成以下几种结构表达。 (A)It is clear/certain/likely /true/surprising that… （B）It is a pity/shame /good idea/no wonder that ...
The question of whether they are male or female is not important. I have not decided whether to go or not.
⑥ whether可引导一个让步状语从句表示 “不管”、“无论”，而if不能，但可以 引导一个条件状语从句表示“如果”如：
• (4)同位语从句 • 就是在句中作同位语的从句。它通常有放在thought, idea, news, word(=news), plan, doubt, question, fact, suggestion, belief等抽象名 词的后面，说明这些词的具体内容或含义。同位语从句大多由that引 导，也可由whether, how, when, where, why等引导，但不能由which 引导。如： • The idea that the earth is round is not a new one. “地球是圆的”这种 观点并不新鲜。He must answer the question whether he agrees to it or not. 他必须回答他是否同意此事这们一问题。 • I have no idea when he will set out. 我不知他什么时候出发。 • 注：有时，同位语从句并不紧跟在它所说明的词的后面。如： • The whole truth came out at last that he was a wolf in sheep’s clothing. 真相终于大白了，他原来是一只披羊皮的狼。
名词性从句详解及练习
各类从句详解英语从句可以分为名词性从句、定语从句和状语从句三大类：下面我们逐一进行说明：一、名词性从句（主语从句、表语从句、宾语从句、同位语从句）主语从句、表语从句、宾语从句和同位语从句在复合句中的充当的成分和其名称相同，分别作主句的主语、表语、宾语和同位语。
上述这四种从句均被称为名词性从句。
所有的名词性从句均不能用逗号分开，并且它们都用相同的关联词，关联词如下：①主从连词：that (无意义), whether (是否), if (是否)（在句子中不充当任何成分）②连接代词：who (谁), whom (谁), whose (谁的), what (什么), which (哪一个)③连接副词：when (什么时候), where (什么地方), how (怎样), why (为什么)主从连词只起连接作用，连接代词和连接副词除了起连接作用外，还充当从句某一个成分。
另外，可以用whatever, whichever, whoever, who(m)ever等连接代词引导名词性从句，来加强语气。
下面分别对各种名词性从句进行介绍（一）主语从句（subject clause）在主句中用作主语的主谓结构称之为主语从句。
例如：That he will come to the discussion is certain.他来参加讨论是确定的。
That the moon moves round the earth is well known to all of us.月球绕地球转动，这是我们大家都熟知的。
When the meeting is to be held has not yet been decide.会议什么时候召开还没有决定。
主语从句放在句首，句子常常显得比较笨重，因此通常可以把it放在句首，作形式主语，而将主语从句放在后面。
例如上面的句子可以分别改写为：It is certain that he will come to the discussion.It is well known to all of us that the moon moves round the earth.It has not yet been decide when the meeting is to be held.下面再举一些例句：What they are after is profit.他们追求的是利润。
(完整版)高中英语语法总结-名词性从句
名词性从句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。
第一节知识点讲解顾名思义，主语从句在句子中作主语。
有时本身出现在主语的位置上，也有时出于句子结构的考虑退到句子的尾部，前面用形式主语 it 代替。
从句作主语时，谓语动词一般为单数形式。
如 :What I saw was beyond any verbal description.That his hair was turning grey worried him a bit.Why the company denied the contract is still unknown.When and where the government will build a city square is under discussion.It is pretty annoying that a small part of the machine is missing.It remains to be seen whether the new novel will be well received.Tips: 主语从句的 that 绝对不能省去。
因为句子是不能做主语的，故用 that 引导。
若去掉则没有了主语，而宾语从句的 that 可省。
主语从句： That he is right is known to all of us.宾语从句： We all know (that) he is right.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。
高考英语语法一轮复习——名词性从句
名词性从句Noun Clauses一. 基础定义和连接词1. 名词性从句：就是在句子中起名词作用的从句。
2. 名词性从句包括4种从句：主语从句、宾语从句、表语从句、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。
[判断]以下从句类型：1）The truth is that I have been there. ( )2）The fact that she was late surprised us. ( )3) That he will come is certain. ( )4) I know that he will come. ( )3. 名词性从句的连接词有：从属连词（不做成分）：that （无意义）,whether, if （是否）….连接代词（在从句中做主，宾，表，定）：what, who, whom, whose, which, whatever, whoever, whichever连接副词（在从句中做状语）：when, where, how , why二. 名词性从句位置和特点●主语从句：1.可直接放在句首。
2.主语较长时通常用It作形式主语，而将主语从句放在后面。
1). he knows Japanese is known to all.2). surprised me was to see him here .3) he is coming doesn’t matter much.4) It remains a secret they climbed up the mountain.●宾语从句：可做动词,介词和部分（表情感态度的）形容词词的宾语。
I want to know when we will start.Everything depends on whether we have enough time.I’m afraid (that) I have made a mistake.注意：如果宾语从句后面有宾补要使用it 作形式宾语而将从句放到宾补后面。
高中英语语法---名词性从句详解
名词性从句详解名词性从句包括主语从句、表语从句、宾语从句、同位语从句。
其关联词有连接词that，if，whether；疑问代词who，what，which和疑问副词when，where，how，why等。
一.语法讲解1.主语从句主语从句在句中做主语。
它可以放在主句谓语动词之前，但多数情况由it作形式主语，而把主语从句放在主句之后。
例如：Who did that is known to all.It is interesting that you should like him.2.表语从句表语从句在句中作表语，位于主句中的系动词之后。
如：The question is who can complete the difficult task.表语从句不能用if引导，但可用as if引导。
例如：He looked as if he was going to cry．3.同位语从句同位语从句跟在名词后面，进一步说明该名词的具体内容。
引导同位语从句的名词主要有fact，news，promise，idea，truth等。
连接词用that（不用which），及连接副词how，when，where，why等。
例如：His delay is due to the fact that the car went wrong halfway．The news that our team has won the match is true.She asked the reason why there was a delay．4.宾语从句1.宾语从句在句中作及物动词或介词的宾语。
例如：We can learn what we did not know．He will talk to us about what he saw in the U.S.如果主句的谓语动词是及物动词make，find，see，hear等，则把宾语从句置于宾语补足语之后，用it作为形式宾语。
高中英语语法之名词性从句
whether or not 连在一起引导宾语从句时不用if
练一练: if / whether 1. I asked her _if_/__w_h_e_t_h_e_r she had a bike. 2. We’re worried about _w_h_e_t_h_e_r_ he is safe. 3. I don’t know _w__h_e_t_h_e_r___ he is well or
1.Everyone knew what happened and that she
was worried.
2.The reason lies in that she works harder
than the others do.
3.I think it necessary that you should read English
• 以上三种句型表建议，要求，责任，义务，或愿 望从句谓语常用should + do, should 可以省略。
• It is suggested that you (should) take it.
• It is necessary that you should stop.
D. It +happened( occur to / seem/ matter/ appear…)+ that / wh-clause
• C. it + be + p.p ( known/ said/reported/ believed/ suggested/ stressed …) + that/ wh-从句
高中英语语法-名词性从句
名词性从句名词性从句的功能相当于名词词组。
在句中作主语；宾语；表语和同位语。
因此，主语从句；宾语从句；表语从句和同位语从句通称为名词性从句。
第一节主语从句引导主语从句的连接词有：that, whether, who, which, what, when, where, how, why等。
That she was invited to the ball made her very happy.Whether he will come to the ball has nothing to do with me.Whoever wants to see the film may get a ticket free.Which team will win the match is still unknown.What interests you doesn’t interest him.Where they had stayed was still unknown.When they will have a meeting hasn’t been decided.注意：1从句作主语谓语动词用第三人称单数形式。
Who will go is not important.2为了调节句子平衡，常用it作形式主语。
It is a pity that he didn’t come yesterday.It’s necessary that every League member (should) take the lead and work well.It’s suggested that a modern hotel (should) be put up at the foot of the hill.3陈述句部分的主语是从句时，其反意疑问句部分的主语用it.How he became a scientist is known to us all, isn’t it?主语从句习题1.________ 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. This[参考答案] 1-10 CBACD DDCAA 11-20 CBDAC BDCAC第二节宾语从句作动词、介词或形容词宾语的从句。
高中英语语法——名词性从句
①that 引导同位语从句时，是连词，不作成分，只起连接作用，that不能省。 that 引导定语从句时, 是关系代词,作主语或宾语。作宾语时常可以省略。 ②定语从句的先行词可以是任何名词或代词；同位语从句前面的名词必须是 抽象名词，常考的有消息(news/ word/ information/ message)、事实(fact/ truth)、 观点(opinion/ view/ thought/ idea/ belief)、希望(hope/ wish)、问题(question/ problem/ doubt)、请求(request/ requirement/ demand/ desire)、建议(advice/ suggestion/ recommendation/ proposal)、承诺(promise)等。
who/ whoever的区分 whoever强调的是人，who表示疑问谁
_W__h_o_e_v_e_r__ could solve the problem will be rewarded. __W__h_o_____ will solve the proble is unknown. __W__h_o_e_v_e_r_ breaks the law, he will be punished.
高中英语语法知识之名词性从句
名词性从句相关概念名词性从句：在复合句中起名词的从句叫做名词性从句。
包括：主语从句、宾语从句、表语从句、同位语从句。
名词性从句引导词：●连接词 that引导名词性从句时，只起连接作用，没有任何意思，也不充当句子成分。
I hope (that) you enjoy your holiday.That he likes you is very obvious.●连接词 whether, if引导名词性从句时，不充当句子成分，但有自己的意思，表示“是否”He asked whether [if] I would show him the way.Whether it will do us harm remains to be seen.●连接代词 who, whom, whose, which, what, whatever, whoever, whomever, whichever引导名词性从句时，均有各自的意义，在从句中作主语、宾语、定语等。
如：Who broke the glass yesterday is not clear.She will give whoever needs help a warm support.●连接副词 when, where, why, how, however, whenever, wherever引导名词性从句，也各自有自己的意义，在从句中作状语。
The question is how we should carry out the plan.When she’ll be back depends much on the weather.宾语从句★位置：A. 作动词宾语He has informed me when they are to discuss the work plan.注意：doubt（怀疑）的肯定句接if/ whether引导的宾语从句，但否定句和疑问句接that引导的宾语从句。
高中英语语法总结-名词性从句
名词性从句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。
高中英语定语从句和名词性从句综合训练名词从句名词从句有四类：宾语从句、主语从句、表语从句、同位语从句。
例如：宾语从句：I don’t know where he will go.主语从句：Where he will go is unknown.表语从句：The problem is how we can get so much money.同位语从句：We all feel sorry about the news that he failed in the game.下面几点是学习名词从句要加以注意的：1．w hether和if都可以引导宾语从句表达“是否”意，（即引导宾语从句时if和whether 可以互换）但以下几种名词从句要用whether（不用if）引导：（1）引导主语从句，且在句首时。
例：Whether he has won the tennis is not known.(但It is not known whether/if he has won the tennis).（2）引导表语从句时。
例The problem is whether he can get a job.（3）引导同位语从句时。
例：I have no idea whether he will come.（4）介词后的whether从句。
例：I worry about whether I hurt her feelings.2．位于句首引导主语从句的that不可忘。
例如：That he got the first place in the competition surprised all of us.3．在“It is suggested/proposed/ordered/a pity/no wonder/necessary/strange/…＋that从句”结构中，that从句谓语有时用（should）do这样的虚拟语气形式。
高中英语语法名词性从句讲解
高中英语语法名词性从句讲解
高中英语语法名词性从句讲解
名词性从句相当于名词，可分别作主句的`主语、表语、宾语和同位语。
因此，名词性从句可分为主语从句、表语从句、宾语从句
和同位从句。
1. 连接代词：who， whose， whom， what， which.有词义，在从句中担任成分，如主语、表语、宾语、或定语等。
2. 连接副词：when， where， why， how.有词义，在从句中
担任成分，作状语。
3. 连接词：that， whether， if， as if.that 无词义，在
从句中不担任成分，有时可省略；if （whether）， as if虽有词义，但在从句中不担任成分。
注意：连接代词与连接副词在句中不再是疑问句，因而从句中
谓语不用疑问式。
连接代词与连接副词在从句充当句子成分，连接
词whether 和if（是否），as if（好似）在从句中不充当句子成分，只起连接作用。
根据句义，如果连接代词与连接副词，whether、if 和as if都用不上时，才用that作连接词（that本
身无任何含义）。
1. 主语从句在复合句作主语。
e.g. Who will go is not important.
2. 用it作形式主语，主语从句放在句末。
e.g. It doesnt matter so much whether you will e or not.
3. that引导主语从句时，不能省略。
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高中语法系列之名词性从句
一.名词性从句考查的焦点主要有以下六方面
1. 考查名词性从句的语序问题
2. 考查引导词that与what的区别
3. 考查it在名词性从句中作形式主语和形式宾语的用法
4. 考查whether与if的区别
5. 考查名词性从句中的疑问词+ever引导的名词性从句与no matter+疑问词引导的状语从句的区别
6. 考查名词性从句的虚拟语气问题
二.名词性从句的含义及连接词
名词性从句的含义:
在复合句中起名词作用的从句叫做名词性从句。
它包括主语从句、宾语从句、表语从句和同位语从句。
引导名词性从句的连接词可分为四类：
1. that（无含义，不充当成分）
2. whether, if（有“是否”的含义，但不充当成分）
3. 连接代词：what, whatever, who, whoever, whom, whomever,whose, which,whichever.（在从句中做主语、宾语、表语和定语）
连接副词：when, whenever,where,wherever, how, however,why（在从句中做状语）
4. as if,as though,because（不充当成分，在名词性从句中只引导表语从句）
三. 四类名词性从句语法要点
1.主语从句
在整个句子中用作主语的从句叫主语从句。
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。
it作形式主语：
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。
It is clear that he is innocent in the accident.
很明显，他在这场事故中是无辜的。
2. 宾语从句
在整个句子中用作宾语的从句叫宾语从句。
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。
it作形式宾语：
在“主语+谓语+宾语+宾补”的句型中，如果宾语是从句的形式，则必须用it做形式宾语，把真正的宾语即宾语从句置于句末。
We found it impossible that the so much work will be finidhed in one day.
我们发现一天之内完成这项工作不可能。
3. 表语从句
在整个句子中用作表语的从句叫表语从句。
The fact is that we have lost the game.
事实是我们已经输了这场比赛。
That is why he didn’t come to the meeting.
那就是他为什么不到会的原因。
It looks as if it is going to rain.
看上去天要下雨了。
This is because he has been working hard these days.
这是因为这些天他一直工作很努力。
注意：because，as if 和as though在名词性从句中只能引导表语从句。
4. 同位语从句
在整个句子中用作同位语的从句叫同位语从句。
同位语的含义：在句子中，如果有两个名词，并且后一个名词是对前一个名词的解释说明，它们两个指的是同一个人或同一个物，那么，后面的名词就叫前面名词的同位语。
例如：This is my friend, Tom.（Tom是my friend 的同位语。
）
可用于同位语从句的名词有advice、demand、doubt、fact、hope、idea、information、message、news、order、problem、promise、question、request、suggestion、truth、wish、word等抽象名词。
The news that we won the game is exciting.
我们赢得这场比赛的消息令人激动。
I have no idea when he will come back home.
我不知道他什么时候回来。
The thought came to him that Mary had probably fallen ill. 他想到可能玛丽生病了。
同位语从句和定语从句的区别：
that作为关系代词，可以引导定语从句，充当句子成分，在从句中作宾语时可以省略；that 引导同位语从句时，起连词的作用，没有实际意义，不充当句子成分，一般不能省略。
试比较下面两个例句:
I had no idea that you were here．
我不知道你在这里。
（that无含义，that you were here 指的就是idea，所以是同位语从句，不能省略that）
Have you got the idea（that）this book gives you？
这本书给了你想法吗？
（that指的是the idea，that引导定语从句，作宾语，可以省略）
四. 连接词that在名词性从句中可以省略的三种情况
1.it 做形式主语，that引导主语从句时
It is said (that) he has been studying abroad.
据说他一直在国外学习。
2.动词宾语从句中
I think(that) you have much to improve in English. 我认为你的英语需要提高的有很多。
3.形容词宾语从句中
I am afraid (that) I will be late.
恐怕我要迟到了。