主语从句名词性从句包括：主语从句、表语从句、宾语从句和同位语从句。引导名词性从句的连词有：A.连词：that, whether, if（这三个词都不作从句的成分，同时，that无含义，而whether和if都表“是否”）B.疑问代词：who, whom, whose, what, whichC.疑问副词：when, where, why, how（一）主语从句：在复合句中充当主语的从句。1.that引导主语从句that引导主语从句时不同于其他的连词，既无词义也不作成分，只起单纯的连接作用，且通常不可以省。为了强调that引导的主语从句而置之于句首时，that不可省。That the driver could not control his car was obvious. 很明显司机不能控制住他的车了That she was chosen made us very happy. 她被选上让我们很高兴That he will come is certain. 他要来已经千真万确了通常，that引导主语从句时用it做形式主语，把从句置于句尾
