名词性从句第一节主语从句引导主语从句的连接词有：that, whether, who, which, what, when, where, how, why等That she was invited to the ball made her very happy.Whether he will come to the ball has nothing to do with me.Whoever wants to see the film may get a ticket free.Which team will win the match is still unknown.What interests you doesn’t interest him.Where they had stayed was still unknown.When they will have a meeting hasn’t been decided.注意：1从句作主语谓语动词用第三人称单数形式。
Who will go is not important.2为了调节句子平衡，常用it作形式主语。
It i s a pity that he didn’t come yesterday.It’s necessary that every League member (should) take the lead and work well.It’s suggested that a modern hotel (should) be put up at the foot of the hill.3陈述句部分的主语是从句时，其反意疑问句部分的主语用it.How he became a scientist is known to us all, isn’t it?第二节宾语从句作动词、介词或形容词宾语的从句。
以连词 that who whom whose what 等引导，在句子中充当宾语I think (that) you will like the pictures.I feel it important that they finish their own task in time.They are worrying about whether they can get there in time.You can write about whatever topic you can think of.一宾语从句三原则：语序；时态；引导词。
1.语序：宾语从句用陈述句语序。
I wonder what he is writing to me about但是：what’s the matter/wrong (with)……语序不变.The owner came up to see what was the matter with me/what was wrong with me2.时态：宾语从句谓语动词的时态与主句谓语动词的时态保持一致。
(1).如果主句的谓语动词是一般现在时或一般将来时，宾语从句用它本身的时态。
I hear he will come back in an hour.(2).如果主句的谓语动词是一般过去时，宾语从句则用相应的过去时态。
She said that he had never been to the Great Wall.(3).如果宾语从句的内容是客观真理时，宾语从句仍然用一般现在时。
The teacher told us that the earth goes around the sun. / light travels faster than sound.3.引导词：（1）由that引导（2）由if/whether引导（3）由特殊疑问词引导二 it在宾语从句中的应用：1. vt.+it+adj./n.+that-clause 或wh-clause。
She has made it clear that she will have nothing to do with him.2.i)在主谓宾结构中，有一些习惯上不以that-clause或 wh-clause从句直接作宾语的动词，如果要接宾语从句，往往需要在从句前加上形式宾语it. The newspapers have it that some Japanese firms have gone bankrupt.报纸说有几家日本公司已破产这类动词还有：have（表明，坚持说）,take（认为）,hide（隐瞒）,love ,like，dislike, hate, enjoy ii) 在主谓宾结构中, 如果谓语动词是短语动词，即动词+介词，一般不能that接从句。
如果接从句，必须加上形式宾语it. I will answer for it that Lao Ma will accomplish the task.我担保老马能完成这项任务Look to it that you make no more similar mistakes.注意今后你不再犯类似的错误了I am counting on it that you will come.我期待着你的到来这类动词还有：depend on, see to etc.iii)某些固定搭配之后如果接that宾语从句,也必须使用作形式宾语it.We owe it to you that there wasn’t a serious accident.这次事故没造成严重的后果全靠你I didn’t send you an invitation, as I took it for granted that you would be coming.因为我认为你当然会来,所以没有给你发请柬三1 否定的转移当主句的谓语动词是think, believe, suppose, expect, imagine等表示看法的动词时,宾语从句中谓语动词的否定式,习惯上前移到主句的谓语动词上.I don’t think that he will be back until nine.2 复杂疑问句/双重疑问句特殊疑问词+do you think/ believe/ suppose/imagine etc+其它部分（陈述句语序）?Who do you guess that girl in red is?Who do you imagine will speak at the meeting tomorrow?3 ----Will they be ready tomorrow?----Yes, I think so. (Yes, I think that they will be ready tomorrow)so 用来替代某一些动词(think, believe, suppose, imagine, hope etc) 后面的that从句.----Will they attend the meeting next month? ----No, I don’t believe so (I believe not)在替代否定概念，既可以用so，也可以用not.但是：在hope和be afraid后在替代否定概念只能是not，不能是so.----Do you think we’ll have bad weather? ----I hope not.----Have you got a work permit? ----I’m afraid not.第三节表语从句含有表语从句的复合句，其主句的主语常常用fact, idea, opinion, problem, question, reason, result或者由what引起的主语从句。
引导表语从句连接代词或者连接副词除常用that以外,who, which, what, whether, when, where, why, how, because, as, as if/as though等。
如：The chance is that one smoker in four will die from smoking.What we want to know is whether your products came up to the standardShenzhen is no longer what it used to be.This is how they overcame the difficulties.It sounds as if/though somebody was knocking at the door.注意：先说结果，后说原因，用This/That is because…先说原因，后说结果，用That/This is why…当主语是reason时，引导表语从句的连接词只能用that ，如He is absent. This is because he is ill.// He is ill. That is why he is absent.// The reason why he is absent is that he is ill. 第四节同位语从句1 先行词与连接代词或者连接副词的选择常见的可以跟同位语从句的名词有：fact, news, hope, belief, truth, message, word, idea, doubt, question, problem, reason, order, suggestion, 等。
引导同位语从句连接代词或者连接副词除常用that以外,who, which, what, whether, when, where, why, how等。
如：I have no idea whether he can manage to do that himself.I have no idea where he spent the night.The question how the students could improve their spoken English is very important2 同位语从句与定语从句的区别He made a decision that surprised all of us.He has made a decision that he will set up a new factory.同位语从句说明名词的具体内容。
that和whether只起连接作用，不充当任何成分，不能省略，也不能用which或if代替；其他的连接词在同位于从句中作句子成分，但不是指代前面的名词，而是有自身疑问意思。