宾语从句的引导词与主语从句的引导词在从句中应用上是不是一样的？

1.that引导陈述句。如： He said that he was honest.
2.if/whether引导一般疑问句。如;He asked me if /whether I knew the answer.
3.特殊疑问词，如：what,where when how,why...如：
He asked me when we would start.
4.to/not to 引导祈使句。如：The teacher asked me to sit down.
He asked me not to see.

引导主语从句连词有that,whether,who,what,whatever等
宾语从句：多为that,可以省略
表语从句：be动词的改变形势
定语从句：that,who,whom,whose,where,when,which...
状语从句：that,when,where等可以表示状态的疑问词等

主语从句(Subject Clause)

定义:如果一个句子在复合句中充当一个主语,那么这个句子就是主语从句.

第一部分：常规主语从句，即句子在复合句中充当一个主语

（1）That he finished writing the composition in such a short time surprised us all.

（2）Whether we will go for an outing tomorrow remains unknown.

（3）Who will be our monitor has't been decided yet.

（4） Whom we must study for is a question of great importance.

（5）What caused the accident remains unknown.

（6）Whatever you did is right.

（7）Whose watch was lost is unknown.

（8）What we need is time.

（9）What we need are good doctors.

小结:

（1)引导主语从句连词有that,whether,who,what,whatever等

（2)连词位于句首不能省略

（3)主语从句大多数情况下视为单三,但也有例外,如例9

第二部分：为了防止句子头重脚轻，通常把形式主语it放在主语位置，真正主语搁置于句末

（1）It is certain that he will win the match.

（2）It is true that he has made a very important discovery in chemistry.

（3）It is very likely that they will hold a meeting.

（4）It is strange that he should do that.

（5）It is important that we all should attend the meeting.

（6）It is strange that the man should have stuck to his silly ideas.

（7）It is a pity that we won't be able to go to the south to spend our summer vacation.

（8）It is still a mystery what caused the accident.

（9）It is said that he has gone to shanghai.(=He is said to have gone to shanghai)

（10）It is known to all that the gun powder was first invented by the Chinese.

（11）It is suggested that the work should be done with great care.

（12）It seems that he has seen the film.(=He seems to have seen the film)

（13）It happened that the two cheats were there. (=The two cheats happened to be there)

小结:

（1)以that 引出的主语从句,常以形式主语it引导.  It is +形容词/名词/某些动词ed + that 从句.

（2) 在有些that从句中要用虚拟语气  (should+do/should+have done)例句4,5,6,11.

当然不一样，主语从句在句子中担当主语的是一个从句,这个从句就叫做主语从句 同样的宾语从句在句子中但当宾语的是一个从句，这个从句就叫做宾语从句， 还有，主语从句中不能省略引导词，宾语从句可以