Section Ⅲ Grammar——名词性从句
语 境 自 主 领 悟 先观察原句 后自主感悟 ①What we find out from space research is 1.句①②为主语从句，句③④⑤important for us on Earth. 为宾语从句，句⑥⑦为同位语②It's well-known that the ancient Chinese invented 从句，句⑧⑨为表语从句。 the rocked. 2.句②③⑥⑧中的引导词为连③We think it probable that he is dead. ④The teacher showed us the controls of the spacecraft and explained how gravity worked. ⑤They insisted that everyone (should) come to the party. ⑥The proposal that we (should) import more equipment from abroad is to be discussed at the meeting. ⑦I have no idea when she will be back. 接词，在从句中不作成分，句①⑨中的引导词为连接代词，句④⑦中的引导词为连接副词。 3.句②③中使用了it作形式主语或形式宾语，而真正的主语从句或宾语从句后置。 4.句⑤中的that可省略，其他句⑧The question remains whether they will be able 中的that一般不可省略。 5.句⑤⑥中的从句使用了虚拟to help us. ⑨The problem is who we can get to replace her. 语气。
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。
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考点一 名词性从句的引导词 引导名词性从句的连接词分为三类： 1．连词：that，whether，if
2．连接代词：what，whatever，who，whoever，whom，whose，which 3．连接副词：when，where，how，why
That she became an artist was due to her father's influence. 她成为画家是受了她父亲的影响。
What we will do tomorrow depends on the weather. 明天我们做什么得看天气。 When we arrive doesn't matter. 我们什么时候到无关紧要。 [名师点津]
(1)名词性从句中用陈述语序；
(2)连词that，whether，if在句中只起连接作用，不充当句子成分； (3)连接代词和连接副词在句中充当句子成分。 [即时演练1] 用适当的连接词填空 ①The village is where I was born.
②Whoever comes to the party will be welcome. ③What he said made me excited. 考点二 主语从句
1．作句子主语的从句叫主语从句。
Where the English evening party will be held has not yet been announced. 还没有宣布英语晚会将在哪里举行。
2．主语从句可以放在主句谓语动词之前，但有时为避免句子头重脚轻，常用it作形式主语，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。
It's a pity that he can't attend the meeting. 他不能参加会议，真是遗憾。 [即时演练2] 用适当的连接词填空
①What we actually need now is not a skirt but a new pair of shoes. ②Whether it is true remains a question.
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③Has it been announced when the plane are to take off? ④It is certain that she will do well in the exam. 考点三 宾语从句
1．由连词that引导的宾语从句 that在以下情况中不能省略：
(1)当主句谓语动词带有两个或两个以上宾语从句时，可以省略第一个that，其他不能省略。
The teacher told the students (that) they should hand in their homework the next day and that the homework must be signed names by their parents.
老师告诉学生他们要在第二天交上作业，并且作业必须由家长签名。 (2)当it作形式宾语时。
She made it clear that it had nothing to do with her. 她表明这件事和她没有任何关系。 [名师点津]
在demand，order，suggest，decide，insist，desire，request，command等表示要求、命令、建议、决定等意义的动词后的宾语从句中谓语动词常用“(should＋)动词原形”。
I insist that she(should)do her work alone. 我坚持要她自己工作。
2．who，whom，which，whose，what，when，where，why，how，whoever，whatever，whichever等连接代词、连接副词引导的宾语从句相当于由特殊疑问句转化而来，但应注意句子要用陈述语序。
She will give whoever needs help a warm support. 凡是需要帮助的人，她都会给予热情的支持。 3．if和whether引导表示“是否”的宾语从句
用whether或if引导的宾语从句，其主语和谓语的顺序也不能颠倒，仍保持陈述语序。whether与if在作“是否”讲时，在下列情况下一般只能用whether，不用if：
(1)引导主语从句并在句首时； (2)引导表语从句和同位语从句时；
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(3)引导从句作介词宾语时； (4)后紧跟“or not”时； (5)后接动词不定式时。
Everything depends on whether we have enough money.一切要看我们是否有足够的钱。
4．宾语从句中的时态与主句时态的呼应
当主句动词是现在时时，从句应根据具体情况使用不同时态。当主句动词是过去时(could，would除外)时，从句则要用相应的过去时态；但当从句表示的是客观真理、科学原理、自然现象，则从句仍用一般现在时。
The teacher told us that Tom had left for America. 老师告诉我们汤姆已经离开，去美国了。 The teacher said that the earth goes around the sun. 老师说地球绕着太阳转。 5．否定转移
当think，believe，suppose，expect，fancy，imagine等动词的主语为第一人称，且本身为一般现在时时其后的宾语从句的否定词通常转移到主句中，即主句的谓语动词用否定式，而从句的谓语动词用肯定式。其反意疑问句一般与宾语从句一致。
I don't believe he'll come.我想他是不会来的。 [即时演练3] 用适当的连接词填空
①Everything depends on whether we have enough money. ②She always thinks of how she can work well. ③I don't believe that man was killed by Jim，was he? together. ④I feel it a pity that I haven't been to the get-⑤I hate it when they talk with their mouths full of food. 考点四 表语从句
whether，that，because，as，as if，as though引导表语从句的连接词有wh-疑问词，等。
The fact is that we have lost the game. 事实是我们已经输了这场比赛。
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[名师点津]
①当主语是reason时，表语从句要用that引导。②表示“建议、要求、命令”advice，recommendation，proposal，demand，requirement，等的名词，如suggestion，request，order等后面的表语从句中，谓语用“should＋动词原形”，其中should可以省略。
③在seem，look，feel，smell，sound，taste等动词后的as if或as though引导的表语从句中，若从句表示一种假设或与事实不符的情况，从句须用虚拟语气。
I felt as if my head were splitting. 我觉得头仿佛要裂开似的。 [即时演练4] 用适当的连接词填空
①The question is whether we should accept their invitation. ②This is why we put off the meeting. ③It looks as if it is going to rain.
④My hometown is no longer what it used to be. 考点五 同位语从句
1．同位语从句一般跟在某些表抽象概念的名词后面，用以说明名词所表示的具体内容。可跟同位语从句的名词通常有advice，demand，doubt，fact，hope，idea等。
I have no idea when he will come back home. 我不知道他什么时候回家。
2．但是当作主语的名词后跟同位语从句，且谓语较短时，为了保持句式平衡，常将同位语从句置于谓语之后。
The thought came to him that Mary had probably fallen ill. 他想到玛丽可能生病了。 [名师点津]
同位语从句和定语从句的区别
(1)定语从句对先行词进行修饰或限定，但它不涉及先行词的具体内容。that引导定语从句，并在从句中充当句子成分(主语或宾语等)，在从句中作宾语时可以省略；
(2)同位语从句表明中心词的具体内容。that引导同位语从句时，只起连接作用，
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外研版高中英语选修8讲义Module 5 Section Ⅲ Grammar——名词性从句
