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.名词性从句的分类如下 （一）主语从句
主语从句的句型.引导词有疑问词wh-及whether/if及that.
1、主语从句在复合句作主语。疑问词引导e.g. Who will go is not important. 2、用it作形式主语，主语从句放在句末。
3、If/whether 引导e.g. It doesn’t matter so much whether you will come or not. 4．It+be+adj(obvious,true,natural,surprising,good,wonderful,funny,likely,certain,probable,etc)/名词词组（no wonder,an honor , a good thing,a pity,etc)+that从句 e.g. It’s certain that she will do well in the exam/It’s no surprise that our team has won the game.
5．It+be+过去分词（said,reported,thought,expected,decided,announced,etc)+that从句
e.g. It’s said that Mr.Green has arrived in Beijing.
Note:that引导主语从句时，在口语和非正式文体中可以省略，但that从句置于开头时不能省略。e.g. That he suddenly fell ill last week made us surprised. （二）表语从句
表语从句的句型及要点 。引导词疑问词wh-及whether及that. 1、表语从句在复合句中作表语，位于系动词之后。疑问词引导的： e.g. The question was who could go there.
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Note: 引导表语从句的连接词that一般不可省去。
e.g. My idea is that we can get more comrades to help in the work.
连接词that一般不能省略，但当主句中含动词do的某种形式时，that可以省略。如： What I want to do is (that) I can go up to him and thank him. 我想做的事是走到身边去感谢他 （三）宾语从句
宾语从句在复合句中作宾语。引导词有疑问词wh-及whether、if(if 和whether 有区别）及that.引导宾语从句的连词that一般可省略。 e.g. I hope (that) everything is all right. Note:以下情况that不可省略：(不考查）
1.当宾语从句的主语是that时。 2.2.当宾语从句中含有主从复合句时 Father promised that I studied harder he would take me to Beijing.
3.当两个或多个宾语从句由并列连词连接时，除第一个从句中的that可以省略外，其余从句中的that都不可以省略。
4当that偶尔作except和in的宾语时。 This book is unsatisfactory in that it lacks a good index. 中，that it lacks a good index就是介词 in 的宾语从句，这当中的that就不能省略。
（四）同位语从句。引导词wh-及whether及that. 同位语从句引导词有疑问词wh-及whether及that.
同位语从句在句中作某一名词的同位语，一般位于该名词（如：news, fact, idea, suggestion, promise等）之后，说明该名词的具体内容。 e.g. I have no idea when he will be back.
The fact that he had not said anything surprised everybody. 名词性从句易混知识归纳
易混点一 ：同位语从句与定语从句的区别
that引导的从句，是定语从句还是同位语从句，我们我们采用“试加 法”，来判断。 The fact that he had not said anything surprised everybody. This is the fact that you must know clearly. 1. when、where、why引导的从句
引导定语从句时，其意义与先行词有关，与先行词的意义基本相同，没有疑问意义；但引导同位语从句时，其意义完全与疑问词相同，即when表示什么时候，where表示哪儿，引导两种从句时，都在从句中做状语。如：
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I still remember the day when I first came to Beijing . 句中的when相当于“on the day”它没有疑问词“什么时候”的意义，因此是定语从句。
I have no idea when she will be back . when与idea毫无意义上的关联，其意思是“什么时候”,因而是同位语从句。 易混点二：reason后面的名词性从句
reason做主语时，后面的表语从句表示原因是要用that引导，一般不用because或why，而用it，this或that做主语时，后面的表语从句可用because或why引导。
1.“The reason +连系动词+that“引导的表语从句。本句型的意思是：理由是：。。。。。。 The reason was that he fell ill.
2.It（或This、That）+连系动词+the reason+why引导的定语从句。本句型意为：这就是。。。。。。的原因（理由）That is the reason why he failed in the contest, 3. It（或This、That）+连系动词+the reason+because引导的表语从句。 本句型意为：这是因为。。。。。。；这是由于。。。。。。的缘故。 That was because he fell ill.
4. It（或This、That）+连系动词+why引导的表语从句。本句型意为：这就是。。。。。。的原因。
That was why he fell ill.
易混点三：what、whatever、who、whoever等引导的名词性从句 我们可以通过与定语从句的转化知道两组在意义上的差别。 Whatever=anything that（无论什么） Whoever=anyone who（无论谁）
Whenever=any time=no matter when（无论何时） Wherever=any place=no matter where（无论何地） 这都是泛指。而what、who、when、where则是特指。如： Who spoke at the meeting is unknown
The person that spoke at the meeting is unknown. Whoever breaks the law will be punished. Anyone who breaks the law will be punished.
注意：1.whatever、whoever、whenever、wherever等常引导主语从句、宾语或表语从句，也可以引导状语从句，等于“no matter +疑问词”。而no matter +疑问词只能引导让步状语从句。
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Eg：Whatever I said/No matter what I said, he wouldn’t listen to me.. 2whoever的宾格还是whoever，一般不用whomever。 易混点 whether与if（不做考查）
二者都可以作“是否”讲，能引导名词性从句，都不能省略。 1. 在及物动词后引导宾语从句时可以互换；
注意：在某些动词后（如:discuss）只能接whether，不能跟if。如： We discussed whether we should close the shop.
2. 引导主语从句、表语从句、同位语从句时都用whether，不用if。如：
The question whether he should come himself or send another man hasn’t been decided. Whether he will win is all the same to me. The question is whether you can go there yourself. 但如果主语从句是有It用作形式主语，if和whether都可以 It is unknown whether\\if she is ill.
3宾语从句中，如果whether后紧跟or not，不用换做if；若whether与or not分开使用，则可以换作if。如： I wonder whether or not he has arrived at the destination. I don’t know whether\\if I can come or not.
4.若宾语从句为否定结构，则多用if，而不用whether。如： I don’t care if he doesn’t show up.（炫耀）
5.在介词后引导宾语从句或与带to的动词不定式结合而构成不定式的复合结构时，只能用whether，而不用if。如：
I haven’t settled the question of whether I will go back home. She doesn’t know whether to get married now or wait. 练习：名词性从句
1. Do you see _____ I mean? 2. Tell me_____ is on your mind. 3. We must stick to _____ we have agreed on. 4. Let me see _____I can repair the radio or not. 5. Keep in mind _____ the teacher said
6. Could you advise me _____ book I should read first?
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7. He was criticized for _____ he had done.
8. Would you kindly tell me _____ I can get to the Beijing Railway Station? 9. Mrs. Smith was very much impressed by _____ she had seen in China. 10. We took it for granted ___ they were not coming. 11. I really don't know _____ I should do next.
12. I'm afraid _____ the little girl will have to be operated on. 13. She walked up to _____ I stood.
14. Can you tell me _____ that gentleman is? 15. We'll give you _____ you need.
16. They want us to know _____ they can do to help us. 17. We must put _____ we have learned into practice.
18. Did she say anything about _____ the work was to be done yesterday? 19. He was never satisfied with _____ she had achieved in her work. 20. These photographs will show you _____ our village looks like. 21. Peter insisted _____ he pay the bill for the dinner. 22. They urged _____ the library open during the vacation.
23. We wish we could have learned _____ you did when we were at high school. 24.1 will describe to you _____ I saw when I go there. 25. From _____ 1 know of him I should say he is a good worker. 26. I will give this dictionary to __ wants to have it. 27._____ they will come here hasn' t been decided yet. 28. _____ was said here must be kept secret.
29. It is still a question _____ we shall have our sports meet. 30. It is strange _____ she have left without saying a word. 31. It is very clear _____ our policy is a correct one. 32. _____ Mr Zhang said is quite right.
33. It's a great pity _____ we won’t be able to finish the task on time.
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