什么叫关系代词在从句中做表语

关系代词有who,whose,whom,that,which,as等等,它们引导的从句充当表语时,就是表语从句,注意,是“它们引导的从句充当表语”,而不是“它们在从句中充当表语”,实际上,关系代词可以在从句中充当任何成分,例如：The problem is who we can get to replace her 。这句话中who充当get的宾语,who引导的从句充当is的表语。He looked as he had looked ten years before。这句话中as充当后一个look（从句中的look）的表语,as引导的从句充当前一个look（主句中的look）的表语。希望我的回答对你有所帮助,