语法讲解_名词性从句.doc

名词性从句名词性从句包括主语从句、宾语从句、表语从句和同谓语从句。一、 连接词连接代词：that, what, who，which, whom，whose, whatever, whoever, whichever等连接副词：whether, how, why, when ,where, wherever等二、连接代词（除that外）和连接副词在名词性从句中都有词义，它们除了引导名词性从句外，还在从句中充当成分，即做主语、宾语、表语、定语和状语。Who will go there is not important.Where she has gone hasnt been known yet.I dont know what I should do.He asked whose dictionary it was.Please tell me when we shall discuss our work plan.I have no idea how soon they are coming.要注意以下几点问题：1、连接代词that的用法：在名词性从句中that 无词义，在从句中不充当任何句子成分，只起连接从句的作用，在宾语从句中，that在口语中可以省略。但在引导主语从句时不能省略。That he was chosen made us very happy.We heard the news that our team had won.The truth is that he is the best in his class.He said (that) he would see me the next week.2、引导宾语从句的that可省略，但及物动词后有两个宾语时， 可省略第一个that, 不省略第二个that；如有形式宾语时，连接真正宾语的that 不能省略。They made it a rule that they got up at six every day.3、由连词that引导的名词从句很少做介词的宾语，只在 except, but , besides介词后看到，其他一些介词的宾语从句如果由连词that 引导，需用it作形式宾语。The girl has not changed at all except that she is no longer so talkative.You may depend on it that they will support you. 4、whether/if的用法常用whether 而不宜用if 的情况：l 引导主语从句，置于句首l 引导表语从句l 介词后的宾语从句l 与or not连用l 引导同位语从句l 动词不定式前注意： doubt“怀疑”接宾语从句时，主句为肯定句用whether 或if ，主句为否定句或疑问句用that。I doubt whether it is true or not.I doubt if it is true.I dont doubt that what he said is correct.Do you doubt that what he said is correct?三、使用名词性从句应注意的几个问题：1） 名词性从句的语序必须是陈述句语序I dont know which team will win the match.That is why he came here.Whoever will go is not important.2)主语从句、宾语从句如果太长，句子常显得笨重，因此，可把他们移到句子后面，前面用it作形式主语或宾语。He took it for granted that what he had done was right. 常用it作形式主语的句型l It be +形容词（true, possible, probable.）+ that 从句l It be + 名词词组（no wonder, a pity, an honor, no surprise, a secret .）that 从句l It be + 过去分词（said, reported, thought, believed, not decided, well-known.）+that 从句l It seems/happens/appears 等不及物动词+that从句l It doesnt matter/makes no difference.+连接代词或连接副词引导的从句l 当that引导的主语从句出现在疑问句中时，用it作形式主语。Whom did it surprise that the naughty boy studied hard later?3)what在名词性从句中有两种意思：“什么”或“所的 ”，前者已经失去了疑问词的含义。I dont know what they are doing.What she said is true.What are to be discussed at the meeting will be announced tomorrow.The problem is what we should do next.Let us see what we mean by “matter”. I dont know what books you have read recently. 注意：what 用作关系代词性质的连接代词，相当于the thing(s) which, that which 或all that，意思是“所的.”， “所的事情/东西”We can learn what we dont know.Mr. Smith is going to give us a report on what he saw and heard in America.What I am not quite clear about is this.It isnt what I want.4) 介词的宾语从来不可用which 和if 来引导，而要分别用what 和whether来引导Are you sorry for what (=the things that) youve done?Everything depends on whether we have enough experience.四、同位语从句通常放在fact, news, idea, order, promise, belief, plan, proposal, suggestion, problem, doubt, thought, question, truth, fear等名词之后， 说明他们的具体内容，同位语从句连接词为that和whether, that 不充当成分，但不能省略。They expressed the hope that they would come over to visit China again.We all know the truth that the earth goes round the sun.The fact that she had not said anything surprised all of us.We were overjoyed at the news that out team had won. They asked me the question whether the work was worth doing.The problem whether it is right or wrong has not yet been decided.An order has come from Berlin that no language but German may be taught in the schools of Alsace and Lorraine. 注意：同位语从句和定语从句的区别是：前者说明名词的内容，后者说明名词的性质特征；前者所用连词 that不是从句中的一个成分，后者所用关系代词that 是从句中的一个成分。试比较：He told me a piece of good news that out team had won.(同位语从句)He told me a piece of good new that Tom had told me the day before yesterday.（定语从句）五、表语从句1）as if/as though 可引导表语从句It looked as if it was going to snow.2）that引导表语从句，that可以省略The truth is (that) I have never been there.特别注意：当the reason 做主语时，其后的表语从句由that 引导，而不用because 引导；但主语如是it (that, this )时，其后的表语从句可由because引导。The reason why he didnt come is that he was ill.Why didnt he come? It was because he was ill.3）注意表语从句中连词how, why, where的译法：This is how we overcame the difficulties.我们就是这样克服困难的。That is why she was absent yesterday.所以她昨天没有。That is where Lu Xun once lived.这是鲁迅曾经居住过的地方。4）whoever, whatever, whichever这些合成词相当于anyone who, anything that 等，它们所指的对象是不确定的，但有强调作用，在现代英语中广泛使用。You can ask whoever is on duty tonight.Give it to whoever you see in the classroom. Whatever ist be done must be done well.All the books are here. You may borrow whichever you like.补充：whoever, whatever, whichever这些合成词除了引导名词性从句外， 还可以引导让步状语从句， 而no matter +疑问词一般只引导让步状语从句。Whatever (=No matter what) h