she went to bed,for she was tired.和he is absent because he is ill.

问题描述:

she went to bed,for she was tired.和he is absent because he is ill.
because 和for 可以换过来使用么?
两句不同连词的用法是不是因为那个逗号?前者是平行,后者是从句?

for和because都可表原因,但二者用法不同
1,because分句位置灵活,二for只能位于主句之后;且for用逗号隔开
2.because可以用来回答why提问的问句,而for不行
3,because前面可以带否定词或是修饰语,而for不行