1、because：
意思：conj. 因为
例句：because of sth/sb：因为某事物/某人
because of the weather 由于天气的缘故
It's all because of him! 这全都是因为他！
all because of sb/sth 都是因为某人/某事物的缘故
2、for:
意思：conj. 因为；由于 prep. 为，为了；因为；给；对于；关于；当作
例句：
He would do nothing, for he knew there was nothing whatever he could do.
他什么事也不打算做，因为他明白没有他能做的事。
He had a great desire to have a home of his own, for he had always lived with my grandmother.
他强烈渴望拥有一个自己的家，因为他一直和我祖母住在一起。
3、on account of：
意思：phr. 由于；因为；为了
例句：
The meeting was postponed on account of the chairman's illness.
由于主持人生病，会议延期了。
On account of his extravagance he was plunged into heavy debt.
由于挥霍浪费，他负债累累
4、since：
意思：conj. 从...以后；自...以来；由于；既然 adv. 此后；后来 prep. 自...以后；从...以来
例句：
We thought that, we'd stop by and see them since we were in the area.
我们想，我们就该顺便去看看他们，因为已经到了这个地方，。