这两个词不引导原因状语从句.而下面这几个才引导 because,as,since ,now that问错了，我想问关系词前有the reason时什么情况下不用why而用which或that，是不是the reason在定语从句中不作原因状语时用which或that，能不能举个句中有the reason用which的例子当the reason这个先行词在定语从句中作原因状语时用why引导。判断作状语可以按照这个方法，即把the reason放在从句中去如果需要在前加上介词for就说明是状语。如 The reason why he came late is that he was caught in traffic jam.（the reason作从句中动词came的状语即句相当于 he came late for the reason所以用关系副词引导）当the reason在从句中作主语，宾语时用关系代词which ,/that引导，如The reason that/which he told us is acceptable.(the reason作从句中动词tell的宾语所以用关系代词)