because,as,since,for,because of有什么不同？

because,as,since,for和because of这几个词在表示“因为”时的用法如下： because用于给出某事的原因。如果某人以Why开头问一个问题，可以用because来回答。because经常用来引出听者/读者不知道的新信息。如果原因是句子里最重要的部分，because引导的状语从句一般放在主句后面。例句： 'Why shouldn't I come?' - 'Because you're too busy.' I couldn't see her expression,because her head was turned. because引导的原因状语从句还可用来说明获知某事的方式： You didn't tell me the truth,because I found the money in your room. 在写作中，原因状语从句有时放在句首，此时as或since用来代替because。通常as和since所表示的原因已为听者或读者所知或者这个原因不是句子里最重要的部分。： As the gorilla is so big and powerful,it has no real enemies. Since she did not make enough money to live in her own house,she went back to live with her mother. 如果在as或since前使用especially或particularly对原因进行强调，应将原因状语从句放在主句的后面： I was frightened when I went to bed,especially as my room was so far up. 在故事中，for有时用来代替because。for引出的是新信息，但它暗示所给出的原因是后来想到的。for从句几乎可以放在括号里且从不放在句首，也不能单独成句。