专题04 名词性从句
【考纲解读】
名词性从句是复合句的一种，前几年高考主要考查宾语从句中用陈述语序以及连接词的选择等问题；近几年对名词性从句的考查趋于复杂灵活，往往把它与定语从句和状语从句的知识点放在一起考查，对名词性从句的考查主要有语序问题、时态的呼应问题和连接词的选择。在单项选择题中，近几年题干语境越来越丰富，句子结构也越来越复杂，其中名词性从句所引起的句子结构的复杂化占了较大比例，命题人侧重于对复杂句子结构的考查，是因为能否分析复杂句子结构是掌握英语语言的重要能力之一，所以我们可以断言，以后的高考题对名词性从句的考查还会倍加青睐。
【知识要点】
一、在句中起名词作用的从句叫名词性从句，它包括主语从句、宾语从句、表语从句和同位语从句。
如：Whether he will come here or not is unimportant to me.（主语从句）
I don’t know what he means.（宾语从句）
I’m glad that you are here.（宾语从句用在形容词之后）
The teacher is satisfied with what you have done.（介词宾语从句）
That was because he was ill.（表语从句）
The news that he got killed in the race surprised us all.（同位语从句）
二、引导名词性从句的连接词
1.that引导的从句如果作介词宾语只可用在except，in，but，besides等少数介词后。如：
I could say nothing but that I’m sorry.
that引导的从句可作it的同位语从句。如：
You may depend upon it that all the goods will be delivered in time.
2.that引导宾语从句时可省略；引导其他名词性从句时，一般不省略，特别是引导主语从句且位于句首时。如：
That the earth is round is true.
The fact that he is a thief got around.
注意：下面一句中，第一个that可省略，第二个that不可省略：
He said（that）he had been working here for ten years and that he wanted to go home.
3.whether与if引导名词性从句时的区别。
（1）在引导宾语从句时whether与if可互换，但如果和or not连用则只用whether。如：I don’t know whether or not he can stay here longer.
（2）如果宾语从句是否定结构，则用if而不用whether引导。如：
He asked me if I wasn’t going there.
（3）介词宾语从句只能用whether引导。如：
I’m not interested in whether he is rich.
（4）引导主语从句、表语从句或同位语从句一般多用whether。如：
The question is whether you can do it yourself.
The question whether he will come here himself isn’t decided yet.
Whether it will do us harm or good remains to be seen.
（5）用it作形式主语时，whether或if都可以引导主语从句。如：
It is not clear to me whether/if he likes the present.
4.注意what/whatever；who/whoever；which/whichever的区别。试比较下列句子： Whoever will go to the concert please signs your name here.=Anyone who will go to the concert please signs your name here.
Who will go to the concert isn’t known.=It’s unknown who will go to the concert.
He won’t believe whatever she says.=No matter what she says，he won’t believe her. Whichhever toy you want is yours.=No matter which toy you want，it is yours.
5.注意how long/how soon/how often/how much的区别。
How long will he stay here?
他将在这里待多久？
How soon can you be ready?
你多久能准备好？
How often do you visit her?
你多长时间去探望她一次？
How much is that dress?
那件衣服多少钱？
6.当主句谓语动词表示不肯定或怀疑时，宾语从句用whether/if引导；表示有把握时用that 引导。如：
I doubt whether/if he can win the match.
I don’t d oubt that he can win the match.
7.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。如：
What you said yesterday is right.
That she is still alive is a fact.
8.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。如：
It is said that President Jiang will visit our school next week.（right）
That President Jiang will visit our school next week is said.（wrong）
（3）It happens...，It occurs...结构中的主语从句不可提前。如：
It occurred to him that he failed in the examination.（right）
That he failed in the examination occurred to him.（wrong）
（4）It doesn’t matter how/whether....结构中的主语从句不可提前。如：
It doesn’t matter whether he is wrong or not.（right）
Whether he is wrong or not doesn’t matter.（wrong）
（5）含主语从句的复合句是疑问句时，主语从句不可提前。如：
Is it likely that it will rain in the evening?（right）
Is that will rain in the evening likely?（wrong）
一、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。被强调部分指人时也可用who/whom。如：
It is a pity that you didn’t go to see the film.你没去看那场电影真是遗憾。
It doesn’t interest me whether you succeed or not.你成功与否对我没有什么吸引力。
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 is ＋不及物动词＋从句
It seems that...似乎……
It happened that...碰巧……
4)it ＋过去分词＋从句
It is reported that...据报道……
It has been proved that...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。如：
据说江主席下周要来我校视察。
It is said that President Jiang will visit our school next week.(right)
That President Jiang will visit our school next week is said.(wrong)
3)It happens...，It occurs... 结构中的主语从句不可提前。如：
他考试没及格。
It occurred to him that he failed in the examination.(right)
That he failed in the examination occurred to him.(wrong)
4)It doesn’t matter how/whether ...结构中的主语从句不可提前。如：
他是不是错了，这一点不重要。
It doesn’t matter whether he is wrong or not.(right)
Whether he is wrong or not doesn’t matter.(wrong)
5)含主语从句的复合句是疑问句时，主语从句不可提前。如：
傍晚有可能下雨吗？
Is it likely that it will rain in the evening? (right)
Is that will rain in the evening likely? (wrong)
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。如：What you said yesterday is right. 你昨天说的是对的。
二、宾语从句
宾语从句就是在复合句中作宾语的名词性从句，通常放在主句谓语动词（及物动词）或介
词之后。
1.作动词的宾语
1)由that引导的宾语从句（that 通常可以省略）,如：
I heard that he joined the army. 我听说他参军了。
2)由what，whether (if)引导的宾语从句，如：
She did not know what had happened. 她不知道发生了什么事。
3)动词＋间接宾语＋宾语从句。如：
She told me that she would accept my invitation. 她跟我说她愿意接受我的邀请。
2.作介词的宾语，如：
Our success depends upon how well we can cooperate with one another.
我们的成功取决于我们的合作情况。
3.作形容词的宾语，如：
I am afraid (that)I’ve made a mistake. 我恐怕是犯错了。
that 引导的从句常跟在下列形容词后作宾语：
anxious，aware，certain，confident，convinced，determined，glad，proud，surprised，worried，sorry，thankful，ashamed，disappointed，annoyed，pleased，hurt，satisfied，content 等。也可以将此类词后的that 从句看作原因状语从句。
4.it 可以作为形式宾语
it不仅可以作为形式主语，还可以作为形式宾语而把真正的宾语that 从句放在句尾，特别是在带复合宾语的句子中。如：
We heard it that she would get married next month. 我们听说她打算下个月结婚。
5.后边不能直接跟that从句的动词
这类动词有allow，refuse，let，like，cause，force，admire，condemn，celebrate，dislike，love，help，take，forgive等。这类词后可以用不定式或动名词作宾语，但不可以用that引导的宾语从句。如：
我非常羡慕他们赢得了比赛的胜利。
I admire their winning the match.(right)
I admire that they won the match.(wrong)
6.不可用that从句作直接宾语的动词
有些动词不可用于“动词＋间接宾语＋that从句“结构中，常见的有envy，order，accuse，
refuse，impress，forgive，blame，denounce，advise，congratulate等。如：
作为一个诚实的人，他给经理留下了很深的印象。
He impressed the manager as an honest man.(right)
He impressed the manager that he was an honest man.(wrong)
7.否定的转移
若主句谓语动词为think，consider，suppose，believe，expect，fancy，guess，imagine等，其后的宾语从句若含有否定意义，一般要把否定词转移到主句谓语上，从句谓语用肯定式。如：I don’t think this dress fits you well.（我认为这件衣服不适合你穿。）
三、表语从句
表语从句是在复合句中作表语的名词性从句，放在系动词之后，一般结构是“主语＋连系动词＋表语从句”。可以接表语从句的连系动词有be，look，remain，seem等。另外，常用的还有The reason is that... 和It is because 等结构。如：
The question is whether we can make good preparation in such a short time.
问题是我们能否在那么短的时间内作好充分的准备。
This is why we can’t get the support of the people.
这就是我们为什么得不到人民支持的原因。
四、同位语从句
同位语从句就是在复合句中作名词的同位语的名词性从句。
1.同位语从句的功能
同位语从句对名词进一步解释，说明名词的具体内容，一般由that引导。如：
The king’s decision that the prisoner would be set free surprised all the people.
国王作出的这名囚犯释放的决定让人们大吃一惊。
2.同位语在句子中的位置
同位语从句有时可以不紧跟在它所说明的名词后面，而是被别的词隔开。如：
He got the news from Mary that the sports meeting was put off.
他从玛丽那里得知运动会要延期举行。
3.同位语从句与定语从句的区别
1)定语从句中的that既代替先行词，同时在从句中作某个成分（主语或宾语），而同位语从句中的that是连词，只起连接主句与从句的作用，不充当句中任何成分。
2)定语从句是形容词性的，其功能是修饰先行词，对先行词加以限定，描述它的性质或特
征；同位语从句是名词性的，其功能是对名词进行补充说明。如：
The news that he told me is that Tom would go abroad next year.
他告诉我的消息是汤姆明年将出国。（第一个that引导的从句是定语从句，that在从句中作宾语）
The news that Tom would go abroad is told by him.
汤姆将出国的消息是他讲的。（同位语从句，that在句中不作任何成分）
【考点诠释】
考点1 主语从句
引导主语从句的连接词主要有三类：连接词that，whether；
连接代词what，who，whose，whatever，whichever，whoever等；
连接副词when，where，why，how等。
1．连接词that，whether引导
①That the college wiU take in more new students this year is true．今年这所大学将招收更多新生是真的。
②Whether he can finish his task on time is of great importance．他是否能按时完成任务非常重要。
特别提示
(1)if不能引导主语从句。
(2)形式主语it替代主语从句。常见的it替代主语从句的句式主要有以下几种：
A．It+系动词+形容词+that从句。如：
It is quite clear that the whole project is doomed to failure．很清楚，整个计划注定要失败。
B．It+系动词+名词+that从句。如：
It is our hope that the two sides will work towards peace．我们的希望是双方能朝着和平的方向发展。
C．It+be+v．ed形式+that从句。如：
It is announced that the plan has been successfully carried out．据宣布计划已经顺利实施。
2．连接代词引导
①What we can’t get seems better than what we already have．我们得不到的东西似乎比我
们拥有的东西好。
②who the letter was from is still unknown．这封信是谁寄出的还不清楚。
③Whichever of you gets here first will get the prize．你们当中第一个到达这里的人将获得奖项。
3．连接副词引导
①How acupuncture reduces and relieves pain is unclear．针灸是如何减轻和解除疼痛的还不清楚。
②why dinosaurs suddenly disappeared still remains a mystery．恐龙为什么突然消失了还是个谜。
考点2 宾语从句
引导宾语从句的连接词主要有三类：连接词that，whether，if等，连接代词what，who，whose，whatever，whichever，whoever等，连接副词when，where，why，how等。
1．连接词that，whether，if引导
①I think(that)you should turn to the teacher for help．我认为你应该向老师寻求帮助。
②I don’t know if/whether he still lives here after so many years．我不知道这么多年后他是否还住在这儿。
特别提示
whether/if都意为“是否”。一般情况下，它们可以互换，口语中常用if，但以下情况中，只能用whether。
(1)与or not紧接连用时。如：
Let me knoW whether or not you can come．请让我知道你是否能来。
(2)作介词的宾语从句时。如：
We are interested in whether you will attend the meeting．我们对你是否参加会议感兴趣。
2．连接代词和连接副词引导
连接代词有what，who，whose，whatever，whichever，whoever等，连接副词有when，where，why，how等。如：
①She asked me whose handwriting was the best in the class．她问我班上谁的书法最好。
②I’11 just say whatever comes into my mind．我想到什么就说什么。
③Do you know when the ancient Olympic Games began?你知道古代的奥运会是什么时间开始的吗?
④I’ve been thinking about how we can make the newspaper more interesting．我一直在考虑如何使我们的报纸更用趣。
3．宾语从句的语序
在宾语从句中要用陈述句语序。如：
①He asked me when we could set out the next day．他问我第二天什么时候可以出发。
②Did you find out where she lost her car?你查出她在哪里丢的车了吗?
4．宾语从句的时态
(1)当主句的谓语动词是一般现在时时，其宾语从句的时态可以是任何适当的时态。如：
①She says(that)she works from Monday to Friday．她说她周一至周五上班。(从句是一般现在时)
②she says(that)she will leave a message on his desk．她说她要在他桌子上留个便条。(从句是一般将来时)
③She says(that)she has never been to Mount Emei．她说她从来没有去过峨眉山。(从句是现在完成时)
(2)当主句的谓语动词是一般过去式时，其宾语从句的时态一般要用适当的过去时态。如：
①He said there were no classes yesterday afternoon．他说昨天下午没有课。(从句是一般过去时)
②He said that he was going to take care of the baby．他说他会去照看这个婴儿。(从句是过去将来时)
③He said that they were having a meeting at that time．他说他们那时正在开会。(从句是过去进行时)
(3)当宾语从句是表达客观真理和规律的句子时，其时态仍旧用一般现在时。如：
①The teacher told us that nothing is difficult if we put our hearts into it．老师告诉我们世上无难事，只怕有心人。
②He said that light travels much faster than sound．他说光比声音传播得快。
特别提示
在使用宾语从句时需要注意下面几点：
(1)动词find，feel，think，consider，make，believe，guess，suppose，assume等后有宾语补足语时，则需要用it作形式宾语，而将that宾语从句后置。如：
①I think it necessary that we take plenty of boiled water every day．我认为每天多喝开水是有必要的。
②I have made it a rule that I keep diaries．我每天写日记成了惯例。
(2)hate，like，take，owe，have，take for granted等表示“喜欢；痛恨；认为”的动词或动词短语和see to表示“注意，留意”后有宾语补足语时，需要用it作形式宾语而将宾语从句后置。如：
①I hate it when they talk with their mouth full of food．我讨厌他们满嘴食物说话。
②When you start the engine，you must see to it that the car is in neutral．启动发动机时，一定要使汽车的离合器处于空档位置。
(3)介词后的宾语从句。如：
①She is always thinking of how she can do more for others．她总想着如何才能为别人做得更多。
②We are talking about whether we admit students into our club．我们正在讨论是否让学生加入我们的俱乐部。
(4)宾语从句的否定转移。将think，believe，suppose，expect，fancy，imagine等动词后面宾语从句的否定词转移到主句中，即主句的谓语动词用否定式，而从句的谓语动词用肯定式。如：
①I don’t think I know you．我想我并不认识你。
②I don’t believe he will come．我相信他不回来。
考点3、表语从句
常由连接词that，whether；连接代词who，whom，whose，which，what，whoever，whomever，whichever，whatever；连接副词when，where，how，why引导。
1．连接词引导
①The reason for his absence is that he hasn’t been informed．他缺席的原因就是他没接到通知。
②The question remains whether they will be able to help us．问题还是他们能否帮我们。
2．连接代词和连接副词引导
①The problem is who will take charge of this shop．问题是谁将接管这家店铺。
②That is when I realized the importance of journalism．那时我才意识到新闻工作的重要性。
特别提示
(1)as/as if/as though引导的表语从句常跟在特定动词后面，
如seem，appear，look，taste，sound，feel等。如：
①It sounds as if someone is knocking at the door．听上去好像有人在敲门。
②At that time，it seemed as though I couldn’t think of the right word．当时我似乎怎么也想不出一个恰当的字眼来。
(2)当主句的主语是reason时，表语从句一般由that引导，这种用法常见于句型The reason why…is that…。如：The reason why he came late was that he got up late．他来得晚是因为起床晚了。
考点4 同位语从句
同位语从句在句子中作某一名词的同位语，一般位于该名词之后，说明该名词的具体内容。这些名词常见的有idea，fact，news，hope，belief，thought，doubt，promise，suggestion，order等。
1．通常用连词that引导同位语从句，that无词义，也不作句子成分，但不能省略。注意从句用陈述句语序。如：
①They expressed the hope that we would go and visit Shanghai again．他们表示希望我们再去访问上海。
②I have no idea that she quit her present job．我不知道她辞掉了现在的工作。
③Give me your promise that you will come to our party this evening．答应我，你今天晚上会来参加我们的聚会。
2．同位语从句还可以用whether，when，where，why，how等引导。如：
①The student asked me the question whether the book Was worth reading．学生问了我这个问题：这本书是否值得一读。
②I have no idea why he was excited at that time．我不知道当时他激动的原因。．
考点5 名词性从句需要注意的事项
1．that的用法。在主语从句、表语从句和同位语从句中that一般不能够省略；在宾语从句中有时可以省略，一般需要注意下面两点：
(1)当that从句作介词宾语时，that不能省略。如：They share little in common except that they are from the same country．除了来自同一个国家之外，他们几乎没有共同点。
(2)当主句谓语动词后接两个或两个以上的宾语从句时，可以省略第一个that，其他的不
省略。如：
I believe(that)you’ve done your best and that things will improve．我相信你已经尽力了，而且情况也会得到改善。
2．that与what的区别。that在从句中不能够充当句子成分，也没有含义；what可以在从句中作主语、表语、宾语或定语，意思是”什么，……的事情”。如：
①The hope that he may recover is not gone yet．他会康复的希望没有消失。(that不充当成分，也无含义)
②Wht he said proved to be true．他所说的话证明是正确的。(what作said的宾语，可以翻译为“……的话”)
3．定语从句与同位语从句的区别。定语从句是从句对其先行词的修饰或限制；而同位语从句是对从句前面的抽象名词作进一步的说明和解释。如：
①The news that our team has won the game Was true．我们队赢了那场比赛的消息是真的。(同位语从句，补充说明news到底是一个什么消息)
②The news that he told me yesterday Was true．昨天他告诉我的那个消息是真的。(定语从句，news在从句中作told的宾语)
③I made a promise that if anyone set me free 1 would make him very rich．我许诺如果谁让我自由，我就让他非常富有。
(同位语从句，补充说明promise的内容)
④The mother made a promise that pleased all her children．妈妈许下了一个令她的孩子们高兴的诺言。(定语从句，promise在从句中作pleased的主语)