名词性从句
名词性从句指的是在主句中起的作用相当于名词的从句，主要包括主语从句，宾语从句，表语从句，和同位语从句。
1.主语从句
（1）主语从句的引导词
在句中作主语的从句称为主语从句。主语从句的引导词主要要有从属连词that, whether, if。连接带刺what,who,who,which,whatever,whichever等，连接副词when,where,why,how等。
（2）that引导的主语从句
That引导主语从句一般位于句首，有时也用it作形式主语而把that从句后置。That在从句中不做任何成分，也没有实际意义，只起连接作用。
That he will come to the conference has excited every one of us.
That in some countries women are still unequally is unfair.
It is likely that there will be a snowstorm tomorrow.
It is no wonder that you have achieved so much success.
It is reported that the coral reefs are being destroyed.
汽车有必要贴膜吗
It appears that we won’t be laid off.
（3）If/whether 引导的主语从句
Whether引导的主语从句可置于句首，但if引导主语从句只能用it作形式主语，而把从句放在句末。
Whether the work can be completed on time is doubtful.= it is doubtful whether/if the work can be completed on time.
（4）连接代词和连接副词引导的主语从句
连接代词或连接副词引导主语从句时要在从句中作一定的成分，且表好似一定的意义。一般连接词在从句中作主语，宾语，表语，定语和状语
What we should do next remains unknown.
Who will be in charge of the project hasn’t been decided yet.
When the new road is open to traffic has not been made clear.
What we can’t get ems better than what we already have.
2.宾语从句
（1）宾语从句的引导词
在句中起宾语作用的从句称为宾语从句。宾语从句的引导词有从属连词that,whether,if,连接代词who,whom,who,what,which,whoever,whomever,whover,whatever,if,连接副词when,where,why,how,whenever,wherever,however等
（2）动词的宾语从句
大多数及物动词可以带宾语从句，有些短语动词也可带宾语从句。宾语从句有时用心事宾语it代替(尤其时宾语后有补足语时)，而将从句后置。That 引导宾语从句时可省略。
He told us that they would help us through the whole work.
He didn’t tell me where the meeting would be held.
Do you know who won the first prize?
Plea find out when ship sails for New York.
He hasn’t made it known when he is going to get married.
I feel it 英语b级高频词汇a pity that i haven’t been to the party.
特别提示
有些动词如appreciate,hate,take,owe,have,e to等后跟从句时要先再从句请安加it.
Plea e to it that the children go to bed by nine o’clock.（请务必使孩子们在九点
之前睡觉）
若宾语从句由wh-引导，其后又to be短语作宾语补足语时，则不可用it代替。
We all consider what河间王 you said to be unbelievable. 对（我们都认为你说的是不可信的）
We all consider it to be unbelievable what you said.错
做人做事的经典语录
（3）介词的宾语从句
一般情况下介词后不跟that,if引导的从句，只能跟wh-类连接词引导的宾语从句。
We are talking about whether we admit students into our club.
Kate was interested in what she had en at the exhibition.
（4）形容词的宾语从句
Sure,certain,glad,plead,happy,afraid,surprid,satisfied,sorry等表示情感的形容词
后的从句常被视为宾语从句。
粉蝶手中的纸老虎
I am not sure whether they’ll agree with with us.
踏实做事I am satisfied that they are telling the truth.
He was glad that she’d come
I am extremely sorry that i have troubled you so much.
（5）If和whether 的区别
介词后的宾语从句一般用whether引导
The teacher worries about whether she had hurt the girl’s feelings.
I am not interested in whether they believe in me or not.
有些动词如leave,put,discuss,decide后的宾语从句常用whether 引导。
The old lady hasn’t decided whether she will live with her daughter in the city.
陈醋泡花生米We are now discussing whether we should group the three companies.
与or not直接连用时，一般用whether不用if
I wonder whether or not we should make it clear that we’ve lost this game.
宾语从句置于句首时，一般用whether
Whether they will join in the Winter Group, i don’t care.
再容易产生奇异的句子中，常用whether引导的宾语从句，而不用if.
Let me know whether you can come.告诉我你是否能来。（如果改成let me know if you can come.则可以理解为“告诉我你是否能来。”或“如果你能来，就告诉我” 两种意义，容易产生歧义）
（6）宾语从句不可省略that的情况
That引导宾语从句时，一般情况下可以省略，但再下列情况中一般不省略。
在learn,suggest,explain,agree,wonder,mean.等动词后引导宾语从句时。
However, he went on to explain that he was not too sure about two things--the grammer and some of the idioms.
I have learned that most of the students who are interested in Chine take interest in English.
宾语较长时
We all think that what the public is badly in need of is nothing but the development of economy.
主句中的状语置于宾语从句之前时。
圣诞老人的由来I realized at once that i had done wrong immediately she told me al about this.
宾语从句中的状语置于该从句句首时。
He told us that, f we could all come to help out, the whole situation would be looking up.
主句位于动词与宾语从句之间有插入语时
When Marx got to England, he found, however, that his english was so limited that he couldn’t go on with his common affairs.
动词带有多个并列的that引导的宾语从句时，除第一个that外，其余的that均不可省略。
Then the teacher began to talk to us about the French language, saying(that) it was the most beautiful tongue in the world,and that we must keep it along us and never forget it.
宾语从句中的主语时this,that或有this that修饰时。
Some people yhink that this part of Scotland with its lakes and mountains is more beautiful than the West of England.
