英语名词性从句ppt

主语从句、表语从句、宾语从句、同位语从句在复合句中起名词的作用，这四种从句合称名词性从句。它们在主句中充当主语、表语、宾语或同位语，都不能用逗号与主句分开。(注：句中划线部分为从句)■主语从句1、定义：先找到句子的谓语，主句的谓语前面的从句，叫做主语从句。Why he left wasn't important.(wasn't是主句的谓语动词，why he left做主语从句)That she became an artist may have been due to her father's influence.(may have been due是主句的谓语动词，that she became an artist做主语从句)2、借助形式主语it，主语从句放在后面①由that引导的主语从句可以放在主语的位置，这时that不可以省略。例如：That prices will go up is certain.that主语从句放在句首的情况不是很常见，绝大部分主语从句都借助形式主语it，主语从句放在后面。It is strange that he knows nothing about it.It is a pity that he can't swim.It happened that he wasn't in that day.It is said that there has been an earthquake in India.在口语中，用it做形式主语时，主语从句的that可以省略。②wh-疑问词引导的主语从句，可以放在句首(第一组)，也可以借助形式主语it(第二组)。第一组：When he'll be back depends much on the weather.How it was done was a mystery.Whether we'll succeed remains to be seen.第二组：It is uncertain whether the game will be held.It's a puzzle how life began.It doesn't matter much where we live.Is it known where he went？■宾语从句1、定义：及物动词(第一组)和介词(第二组)的后面可以接从句做宾语，叫做宾语从句。第一组I guess(that) we'll leave soon.He asked when we would be in London.She informed me (that) she was to send for it the next day.(that可以省略)I'll tell you what I read in today's paper.第二组I'll find out whether she's interested in going.Can you give us a description of what has happened.She was shocked by what she had seen.2、借助形式宾语it，that引导的宾语从句放在后面。I've heard it said that you have won a scholarship.分析：it在句中做形式宾语，said做宾语补足语，that you have won a scholarship是真正的宾语。She has seen to it that all the children are well taken care of.分析：it在句中做形式宾语，that all the children are well taken care of是真正的宾语。■表语从句1、定义：系动词的后面可以接句子做表语，叫做表语从句。The fact is that she never liked him.That is not what I meant.The question is who is responsible for what has happened.She is no longer what she used to be.2、注意：①The reason Hollywood was a good place for making movies was that the sun shines there every day.分析：the reason做主语时，表语从句用that引导。②引导表语从句的that一般不省略。■同位语从句1、定义：有些名词的后面可以跟that引导的从句，说明这个名词的内容，这样的从句叫做同位语从句。所以，只有可以有内容的名词才可以接同位语从句，例如：fact，message，idea，possibility，conclusion，thought，news，order，report，rumor等等。that在从句中不做成分，但是不能省略。He had the feeling that he would not see her again.I've come to the conclusion that it won't be wise to do so.2、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.that引导的同位语从句修饰the rumor，但是主句The rumor spread太短，如果把后面的同位语从句放在the rumor后面，主语太长，给人头重脚轻的感觉。3、在少数情况下，名词性从句的其他关联词也可以引导同位语从句。但if不可以引导同位语从句。You have no idea how worried I was.I have no idea why she left.There is some doubt whether John will come on time.在学习名词性从句时注意下面四点：一、名词性从句要用陈述语序，也就是说：①名词性从句的关联词做主语的话，关联词后面接谓语动词；②名词性从句的关联词不做主语的话，关联词后面接从句的主语和谓语。①I don't know who broke the window.(宾语从句中关联词who做主语，broke是谓语动词)②The little boy told his mother where he found the coin.(宾语从句中关联词where不做主语，where后面接主谓部分he found)二、感叹句做名词性从句时语序不做变化Don't you know how excited I was then？三、时态的呼应某些从句(特别是宾语从句)中的动词时态，常受主句谓语时态的制约。①如果主句谓语动词为现在时或将来时，从句中的谓语可以不受影响。例如：Has he told you when he received the gift？Will you tell me how you two are getting along？②如果主语谓语动词为过去时，从句谓语一般要跟着改为相关的过去时。I didn't know where they lived.He thought he was working for the people.asked him how long he had been waiting.③但是，当宾语从句表示永恒真理时谓语可以不变：This proved that the earth is round.四、当and连接两个that引导的宾语从句时，and后面的that不可以省略She promised (that) she would come and see him sometimes and that she would never forget him.句中的第一个that可以省略，为了清楚地表示出第二个that引导的是宾语从句，第二个that不省略。