because for since都有因为的意思，但在用法上有什么区别，

because for since都有因为的意思，但在用法上有什么区别，because for since都有因为的意思，但在用法上有什么区别，麻烦举例说明，谢谢because， for， since，都有因为的意思，但在用法上有什么区别，麻烦举例说明，谢谢

热心网友

because, since, as和for 1）　because语势最强，用来说明人所不知的原因，回答why提出的问题。当原因是显而易见的或已为人们所知，就用as或 since。　 I didn”t go, because I was afraid.　 Since /As the weather is so bad, we have to delay our journey.2）　由because引导的从句如果放在句末，且前面有逗 号，则可以用for来代替。但如果不是说明直接原因，而是多种情况加以推断，就只能用for。　 He is absent today, because / for he is ill.　 He must be ill, for he is absent today.

热心网友

for 一般表示推断理由, 即根据前边的结果, 推断原因,for所引导的不是充分必然原因,The ground is wet, for it must have rained last night.The day must be broken, for the bird s are singing.