名词性从句精讲在句子中起名词作用的句子叫名词从句(Noun Clauses）。
名词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。
That he will come h ere surprises me. I know that he will come here.The news is that he will come here.The new that he will come here surprises me.一、名词性从句的相同点：1.结构 2.连接词引导名词性从句的连接词可分为三类：从属连接：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二、四大名词性从句的剖析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：That he suddenly fell ill last week made us surprised. 上星期他突然生病了让我们很惊讶。
Whether he will be able to come remains a question.他是否能够来仍然是一个问题。
What he wants to tell us is not clear. 他要跟我们说什么，还不清楚。
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 +形容词+主语从句It is very interesting that he likes such kind of books.（2）It + be +名词+主语从句It is a pity that he missed the lecture.（3）It + be +动词的过去分词+ that从句It is said that they have won the game. （4）It +不及物动词+ that从句It seems that something is wrong with the computer.另注意在主语从句中用来表示必须、理应如此、建议、要求等语气时，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 suggested (requested, proposed, desired, etc.) that…2.宾语从句名词性从句用作宾语叫宾语从句，在句中可以作谓语动词或介词的宾语。
引导宾语从句的连接词与引导主语从句连接词大致一样。
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。
高考重点要求1．掌握主语从句、宾语从句、同位语从句、表语从句的基本句型结构。
2．弄清名词性从句的连词意义，掌握其用法。
3．根据句子语义确定使用何种从属连词。
名词从句分为：主语从句、宾语从句、同位语从句、表语从句。
我们看一下它们的属性。
如：that he failed the entrance examination1)______made all of us surprised.2)He told me____.3)The result is _____.4)Thenews____surprised me.我们在四个句子中可以填入that he failed the entrance examination这个句子，发现都可成立。
从上例不难看出，从本质上讲，这四类句子的属性是相同的，即：都起名词作用，只不过称谓不同,在整个句子中担当成分不同而已。
纵观几年高考，对复合句的考查重在连词，名词从句也不例外，基本上是针对引导词设题。
一引导词的分类：1连接代词：what , who ,whom ,whose , which，whatever,whoever,whichever,且这些词在从句中担当主、宾、表、定语作用。
2．连接副词：why, when , where, how 在从句中充当时间、地点、原因、方式、程度状语。
whether , if在从句中不充当成分，但整个句式中不可缺少，用以体现事件的不确定性。
3．that是名词从句中一个很活跃的词，但它只起连接作用，陈述某一事实，引导宾语从句时某些情况可以省略。
针对如下情况，可进行对比：1)______he will come to call on is uncertain .2)_______he will come to call on us is uncertain.3)_____ he will come to call on us makes us unhappy.从第一句中我们可以看出主语从句本身并不完整，缺少call on的宾语，应加who;第二句中表语为uncertain ,可知主语部分为未知信息，可加入when, why ,how ,whether等;第三句表一种已知事实，故应加入that。
二．that ,whether, if在名词从句中的使用情况1．that在宾从中大多数情况下可以省略，在主、宾、表中不可省去。
但注意以下宾从中that不可省。
I know nothing of himexceptthathe is from Henan.(介词后宾从中的that不可省) ２．whether ,if宾语从句中可换用，但在主语从句、表语从句和同位语从句中不可用if。
但注意在宾语从句中不能用if的情况：It all dependsonwhether they will support us.(从句作介词宾语时不可用if)He doesn't know whetherto stay or not. （后直接跟不定式时，不能用if）Please let me knowifyou like it.(这句是有双重意思的，如果视为宾语从句，就应换为whether.否则就引起歧义。
三．从句的区分1)He tells me his idea ___we reduce the cost .2)We are discussing the idea____hecame up with yesterday.第一句中we reduce the cost应视为是idea内容的一种说明，是同位语从句，而第二句中idea 可视为come up with的宾语，缺少引导定从的关系代词that或which ,当然可以省去关系代词。
四．分类复习中应注意的问题：1.在主语从句中it的使用That he will come to the party is certain。
表意上并没有错误，但实际上并不太符合用语习惯，因此采用it作形式主语，使句式平衡。
It is certain that he will come to the party.同样道理，it 也可用作形式宾语。
2．宾语从句中的情况1）时态的呼应问题。
2）特殊句式：动词suggest, insist, demand, order ,request, require等引起的从句需用虚拟句式主语+should +原形动词,should也可省。
Hesuggestedthat we should pay a visit to that town.(建议)但注意：What he said suggested that he had known the truth.(表明)同样，insist Heinsistedthat we do it at once.(坚持要做)He insisted that he had done nothing wrong.(坚持说一种事实)wish引起从句时从句中时态常转为过去时态。
I wish that there were no examinations in school.How he wishes he had worked hard in junior middle school!强化练习1. It's no longer a question now _____ man can land on the moon. A. that B. if C. whether D. what2. _____he said at the meeting astonished everyone at present. A. What B. That C. The fact D. The matter3. In front of___ remained of my old house, I took some pictures, which called up my childhood. A. which B. the place C. where D. what4. _____ you can go to college this year depends on ___ you are studying hard now. A. That, that B. Whether, whether C. If, if D. Whether, if5. _____has recently been done to provide more buses for the people, a shortage of public vehicles(车辆)remains a serious problem.A. ThatB. WhatC. Though whatD. In spite of what6. I'll tell you _____ he expects will win such and such a match. A. who B. whom C. what D. that7. I didn't quite follow you. What was _____you just said about the place? A. that B. whichC. howD. where8. Maria has to baby-sit. That's _____ she can' t come out with us. A. when B. how C. why D. what9. After ____seemed a very long time, the badly-wounded soldier came back to life. A. that B. itC. whichD. what10. _____she was chosen monitor made him excited. A. What B. That C. IfD. Whether11. I don't think _____Jenny can come home this weekend. A. how B. why C. that D. when12. When I try to find _____ that prevents so many people from taking part in the program, it seems to me that there are two mean causes. A. what it does B. what it is C. why it doesD. why it is13. You should stick to _____you have begun until you succeed. A. which B. that C. whateverD. no matter what14. Someone is ringing the doorbell. Go and see _____. A. who is he B. who he is C. who is itD. who it isA 2. A 3. D 4.B 5. D 6. A 7. A 8.C 9.D 10. B 11.C 12. B 13. C 14. DWhatever与no matter whatIt is generally considered unwise to give a child ___ he or she wants．A．whatever B．no matter what C．whenever D．no matter when此题应选A。