名词从句
名词从句分为主语从句、表语从句、宾语从句、同位语从句。以此举例：
It is clear that he has gone.
The question is when I can leave.
I don’t know who he is.
The news that he will come late upts all of us.重来歌词
一、主语从句
1、由连词that, whether引导的主语从句
It is certain that he will come.
Whether he will come is doubtful.
注：whether引导主语从句，不能用if代替
由that引导的主语从句还能改写成由it做形式主语的从句：
It is true that the earth is round.
这类结构一般有：
①It +be +形容词+that，这类形容词有clear, obvious, likely, true, probable, possible
②It +be + said/believed/reported/hoped/announced/known that…
③It +ems/happens/appears that
④It +be +名词+ that从句
It is accepted belief that wind is air in movement.普遍认为风是流动的空气
2、由连接代词（who，which）和连接副词（when，where，how，why）引导的主语从句，也可以用it做形式主语引导
Who let out the news remained unknown. =It remained unknown who let out the news.
3、由关系代词what, whatever, whoever等引导的主语从句，此类主语从句不能用形式主语it引导，合成词在句子中担任成分
What he said at the meeting is important.—主语从句
The thing that he said at the meeting is important.—定语从句
what =the thing that, whoever=any one who, whichever= anything that,但是等号后面的不能引导名词性从句
（误）No matter who gives us help is welcome.
（正）Whoever gives us help is welcome.
（误）I’ll believe no matter what he says.
（正）I’ll believe whatever he says.
二、表语从句
用于表语从句的连词有that, whether, what, whatever, who, whoever, when, where, why, how等
例：The question is how we can get there.
1、that引导的表语从句
①名词主语+ be+ that 从句
问题性皮肤常用作主语的名词表示事实、真理或看法、观点：fact, truth, idea, opinion, belief, view, feeling, suggestion, plan
②wh-引导的主语从句+ be+ that从句
What surprid me most was that all the pupils were unusually quiet.
2、wh-疑问词引导的表语从句
①This/That +be+ wh- 疑问词引导的从句
This is how you make the Italian pizza.
②名词主语+ be+wh-疑问词引导的从句
The problem is how scientists can keep in touch with the divers under the a.
注：if不能用来引导表语从句
3、as if/as though, becau引导的表语从句
1）as if/as though可以用陈述语气，也可以用虚拟语气
It looks as if it is going to rain.
The patient looked as if he had been ill for a long time.
风景图像2）becau引导表语从句，主句主语不能用reason（reason与becau不见面）
It may be becau I didn’t have a good sleep last night.
The reason why she called me is that she will not attend the party.
如果主句主语是reason，表语从句连接词用that
三、宾语从句
1、连词与主语从句和表语从句一样，但是它与主语从句、表语从句的区别是：
if可以用于宾语从句中，有时可以和whether互换
that在宾语从句中可以省略，主语从句和表语从句中不能省略，that引导的宾语从句常用形式宾语it来引导
2、介词宾语从句嘴唇痒
1）that引导的从句做介词宾语从句
that引导的从句很少做介词的宾语从句，只在except, in, but, besides等少数介词后使用（in that因为…，except that除了…，but that要不是…，除了）
I could say nothing but that I was sorry.
但可跟在带有形式宾语it之后作介词的真正宾语，这类词有e to负责，depend on依靠，rely on依靠，count on指望
例：See to it that the door is safely locked before you go.你走之前一定要锁好门
2）关系代词/副词引导的从句做介词宾语从句
He was satisfied with what I did.
What we should take with us depend on where we’ll stay.
3）不及物动词后跟介词宾语从句
有些不及物动词后边如果跟宾语从句，省去介词
中国著名企业例：I don’t care whether he likes me or not. 比较：I don’t care about him.
I insist that you should learn a cond language.
比较：I insist on your learning a cond language.
3、宾语从句中需要注意的事项
1）宾语从句时态
当主句是现在的时态（一般现在时，现在进行时，现在完成时），从句时态可根据实际情况而定。
当主句是过去的时态（一般过去时，过去进行时），从句的时态要变为相应过去的时态
2）主句是I don’t think…宾语从句
主语必须是第一人称I/we，才能用这样的句型（否定主句，不否定从句）
类似I don’t消释 think…句型的有：I don’t imagine, I don’t believe, I don’t suppo
★注意该句型反意疑问句用法：I 关机英文don’t think you can do that, can you?
3）连词that省略
对于连接词and或but所连接的两个做宾语的that从句中，第一个宾语从句中的that可以省略，
第二个则不能省略
He said (that) he has worked for nearly ten years here and that he wanted to go home.
4）doubt/sure引导的宾语从句，用whether/if和that的区别
★句型：I doubt whether/if…我怀疑……是否……；I don’t doubt that…我毫不怀疑……
I doubt whether he can speak English. 对比：I don’t doubt that he can speak English.
田园派诗人
★句型：I’m not sure whether/if…我不确定……是否……；I’m sure that…我相信……
I’m not sure whether/if the news is true. 对比：I’m sure that he can do it well.
有两种句型：
① be+形容词+that从句
We are certain that we will do well in English writing.
② be+ not+形容词+wh-从句
He is not sure why so many girls want to be air hostess.
此类形容词有：certain, afraid, sure, anxious, worried, surprid, happy, disappointed.
四、同位语从句
与先行词同位或同等的从句称为同位语从句，一般由连词that引导，在从句中不担任成分，不能省略，whether也能引导同位语从句
同位语从句一般有两种：
1、名词+ that引导的从句。常用的同位名词有：answer, belief, doubt, fact, hope, idea, news, order, question, reply, rumo(u)r, thought等
例：The rumor that there’ll be the earthquake soon spread all over the area.
2、名词+ wh-疑问词/how引导的同位语从句
Have you any idea where they are having a rehearsal?
★注：同位语从句与定语从句的区别
