as ,for,since,because的区别
问题描述：
as ,for,since,because的区别
答
as,because,since,for用法区别
前三者引导原因状语从句,for引导的则为并列句.
as表示明显原因,语气较because强,例如：
As it is raining,we’ll stay (at) home.
because表示内在的、必然的因果关系,语气较强,例如：
He has to leave because it is too late.
since表示鉴于某种既定事实而为之,语气较弱,例如：
Since everyone is here,we can begin our lesson.
for只是作为补充说明,不用于某种结果之前,表示判断某种情况的因素,语气较because弱,但较为郑重、正式,不能放在句首,例如：
I’ll stay home,for I must wait for a friend.