名词性从句
【互动导学】
【知识梳理】
在复合句中起词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，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、表语从句、宾语从句和同位从句。 引导名词性从句的连接词
1）连接代词： who, whose, whom, what, which有词义，在从句中必须充当句子成分，如主语、表语、宾语或定语等。
2）连接副词： when, where, why, how有词义，在从句中必须充当成分，只能作状语。 3）连接词： that, whether, if, as if
that 无词义，在从句中不充当成分，做宾语时可省略；
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词，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）。 4）连接代词：whatever, whoever, whomever, whichever 5）语序
名词性从句都必须与陈述句语序相同，即“主语＋谓语”。
【导学】一：主语从句：在复合句中其语法作用是主语的句中，叫主语从句。 【知识点】1：主语从句位于句首
e.g. （1）That he finished writing the composition in such a short time surprised us all.
（2）Whether we will go for an outing tomorrow remains unknown.(注意：不能把whether改为if， 因为if不能引导主语从句)
（3）Whatever you did is right.
（4）Who will be our monitor hasn't been decided yet. （5）What caused the accident remains unknown.
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（6）Which of the two is better remains to be seen. （7）When we will start the work is important.
【知识点】2：为了避免句子头重脚轻，用it作形式主语，主语从句放在句末。
e.g. （1）It doesn’t matter so much whether you will come or not.
（2）It is true that he has made a very important discovery in chemistry.
（3）It is a pity that we won't be able to go to the south to spend our summer vacation. （4）Is it likely that it will rain in the evening ?
【知识点】3：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 +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。 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 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; unusual; certain; evident; surprising; interesting; astonishing, etc. It is doubtful whether she will be able to come. It seems obvious that we can not go on like this. It is necessary that you（should）master the computer.
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。
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; expected; believed; thought; hoped; required; suggested;
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demanded; etc.
例如：It is said that honesty is the best policy.
It is said that thirteen is an unlucky number.
It is reported that over 300 million people in China are suffering from near-sightedness. It is known to all that the earth is round.
【我爱展示】高考题链接：
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
2. 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 3. ________some people regard as a drawback is seen as a plug by many others.( 北京) A．Whether B．What C．That D．How 4. It is uncertain________side effect the medicine will bring about，although about two thousand patients have taken it.(浙江) A．that
B．how C．what
D．whether
【导学】二：表语从句：在复合句中作表语的完整句子，位于be动词或系动词之后，
说明主语是什么或者怎么样。
e.g.（1）The question was who could go there. （2）He has become what he wanted to be ten years ago. （3）She has remained where I stood yesterday for an hour.
（4）His suggestion is that we should stay calm. （5）It seems as if it is going to rain.
（6）The question is whether the enemy is marching towards us. (注意：不能把whether改为if， 因为if不能引导表语从句)
（7）What she couldn’t understand was why fewer and fewer students showed interest in her lessons. 引导表语从句的词有连词that, whether, as if, who, what, which,when, where,how, why等，注意：表语从句中的连词that 不可以省略；连词if一般不用来引导表语从句。
【导学】三：同位语从句：在复合句中作某一抽象名词的同位语，一般位于该名词之后。
（如：promise，message，doubt，belief，reason，possibility，conclusion，thought，order，question，problem，report，rumor，hope，truth，news，fact，idea，suggestion，evidence等）
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e.g. I have no idea when he will be back. The fact that he had not said anything surprised everybody. I've come to the conclusion that it won't be wise to do so. 有时为了保持句子的平衡，同位语从句有时和前面的名词分开。
The rumor spread that a new school would be built here. 1）英语中引导同位语从句的词通常有连词what, who, that, whether等，连接副词 how, when, where等。（注：if不能引导同位语从句。）
2）连词that引导同位语从句,不能省，且在从句中没有任何意义，不充当任何成分。
The idea that you can do this work well without thinking is quite wrong. 3）连词whether引导同位语从句
The questionwhether we should call in a specialist was answered by the family doctor.（注：if不能引导同位语从句）
4）连接代词what, who, whom, whose, which引导同位语从句
1) I have no idea what size shoes she wears. 2) I have no idea which wine is best—it’s a matter of personal taste. 3) The question who will take his place is still not clear. 5）连接副词when, where, how, why引导同位语从句
We haven’t yet settled the question where we are going to spend our summer vacation. I have no idea when they will come . 【我爱展示】
1.【2015安徽】25. A ship in harbor is safe, but that’s not ______ ships are built for.
A. what
B. whom
C. why
D. when
2.【2015福建】29.—1 wonder______ Mary has kept her figure after all these years.
—By working out every day.
A. where won’t accept it.
A. That B. Why C. Where D. How
4.【2015陕西】19. Reading her biography, I was lost in admiration for Doris Lessing had achieved
in literature.
A. what B. that C. why D. how
5.【2015重庆】We must find out Karl is coming, so we can book a room for him.
A.when B. how C. where
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B. howC. why D. if
3.【2015江苏】25. _____ Li Bai, a great Chinese poet, was born is known to the public, but some
D. why
6.【2015四川】8.The exhibition tells uswe should do something to stop air pollution.
A.where B.why C.what D.which 7.【2015北京】33.I truly believe ______beauty comes from within.
A. that B.where C. what D.why
8.【2015北京】35._____we understand things has a lot to do with what we feel.
A. Where B.How C.Why D. When
【导学】四：宾语从句
宾语从句是一种名词性从句，在句中作及物动词的宾语，或介词的宾语，或形容词的宾语。根据引导宾语从句的不同连词，宾语从句可分为三类
【知识点】1：
He said (that) he wanted to stay at home.
She doesn’t know (that) she is seriously ill. I am sure (that) he will succeed.
→由that引导的宾语从句。That只有语法作用，没有实在的意义，在口语
和非正式文体中可以省略。
【知识点】2：
Do you know who (whom) they are waiting foe? He asked whose handwriting was the best. Can you tell me where the No.3 bus stop is? I don’t know why the train is late.
→由连接代词who, whom, whose, what, which和连接副词when, where,
why,how引导的宾语从句。这些连接代词和连接副词在宾语从句中充当某个成分。
【知识点】3：
I want to know if (whether) he lives there. He asked me whether (if) I could help him.
→由if或whether引导的宾语从句。If和whether在句中的意思是“是否”，
在句中不充当任何成分，不能省略。
Whether/if 有时与or 连用，whether有时与or(not)连用，例如： She asked whether you wanted this one or that one.
【知识点】4：宾语从句的语序
宾语从句的语序应为陈述句的语序。例如： I hear (that) physics isn’t easy.
I think (that) you will like this school soon. Can you tell me how I can get to zoo?
Please tell me when we’ll have the meeting.
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