因为 (for the reason that)：“I eat potatoes～I like them.” “Why?” “B～they taste delicious.”“我吃土豆是因为我喜欢土豆。”“为什么喜欢?”“因为味道很好。”B～I was ill， I lost my job. 因为我有病就丢了工作。I said nothing not～I hesitated to tell what I thought， but～I really had nothing to say. 我什么也没说，不是因为我不愿意说出我的想法，而是因为我确实没什么可说。It's～you're doing too much.这是因为你干得太多了。〖同〗as，since，for;

because of (prep) 因为：I stayed at home not～of the rain/illness/what he had said， but～I was tired.我待在家里不是因为下雨/有病/他说了那些话，而是因为我累了。

【用法】because引导的从句通常不置于句首;若置于句首，是为了强调从句，如：Just～I don't complain， people think I'm satisfied.(就因为我不抱怨，人们以为我感到满意了。) 注意，不可说the reason is because，而应把because换为that，如：The reason for my absence was that I was ill. (我缺席的原因是我病了。)

【辨异】1)because of与owing to、due to和thanks to都表示原因，区别主要在于用法。because of (因为)与thanks to(由于)只引导状语，owing to (由于)引导状语，也可引导表语;而due to (因为)则通常只用作表语(在be后)或用在名词后，如：His lateness was due to/owing to the storm. (他迟到是因为暴风雨。) Accidents due to driving at high speed were very common. (由于高速行车而造成的事故是很常见的。) 但现在受过教育的人也开始用due to引导状语了，如：He was late due to/owing to/because of the storm. 2)because与as、since和for的区别见AS。