当陈述部分的主语是不定代词everything,nothing,anything,something时,反意疑问句中的主语一般用it,不用they.如：
Everything seems all right now,doesn’t’t it?
Nothing is kept in good order,is it?
Something must be done to stop pollution,isn't it?
因此,这里的反意疑问句应该是Nothing can help you,does it?