1、because：

　　意思：conj. 因為

　　例句：because of sth/sb：因為某事物/某人

　　because of the weather 由于天氣的緣故

　　It's all because of him! 這全都是因為他！

　　all because of sb/sth 都是因為某人/某事物的緣故

　　2、for:

　　意思：conj. 因為；由于 prep. 為，為了；因為；給；對于；關于；當作

　　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，因為他明白沒有他能做的事。

　　He had a great desire to have a home of his own, for he had always lived with my grandmother.

　　他強烈渴望擁有一個自己的家，因為他一直和我祖母住在一起。

　　3、on account of：

　　意思：phr. 由于；因為；為了

　　例句：

　　The meeting was postponed on account of the chairman's illness.

　　由于主持人生病，會議延期了。

　　On account of his extravagance he was plunged into heavy debt.

　　由于揮霍浪費，他負債累累

　　4、since：

　　意思：conj. 從...以后；自...以來；由于；既然 adv. 此后；后來 prep. 自...以后；從...以來

　　例句：

　　We thought that, we'd stop by and see them since we were in the area.

　　我們想，我們就該順便去看看他們，因為已經到了這個地方，。