名词性从句在句子中起名词作用的句子叫名词从句。名词从句的功能相当于名词词组, 它在复合句中能担任主语、宾语、表语、同位语、介词宾语等，因此根据它在句中不同的语法功能，名词从句又可分别称为主语从句、宾语从句、表语从句和同位语从句。 名词性that-从句 1） 由从属连词that引导的从句叫做名词性that-从句。That只起连接主句和从句的作用，在从句中不担任任何成分，本身也没有词义。名词性that-从句在句中能充当主语、宾语、表语、同位语和形容词宾语。例如： 主语：That he is still alive is sheer luck. 他还活着全靠运气。 宾语：John said that he was leaving for London on Wednesday.约翰说他星期三要到伦敦去。 表语：The fact is that he has not been seen recently. 事实是近来谁也没有见过他。 同位语：The fact that he has not been seen recently disturbs
