why对应的词是because。why作为副词、名词和感叹词，含义有“为什么”、“为何”、“原因”、“理由”、“说明”、“难解的问题”等，而because作为连词，含义为“因为”。
一、why的含义及用法
1、作为副词，意为(用于问句)为什么，为何;(反问，表示不必)何必;(说明理由)为什么，…的原因。
例句：Why were you late?
你为什么迟到？
Why get upset just because you got one bad grade?
何必因为一次成绩不好就想不开呢？
That's why I left so early.
这就是我早早离去的原因。
2、作为感叹词，意为(惊讶、不耐烦等时说)哎呀，呦，哟，嗨。
例句：Why Jane, it's you!
呦，简，是你呀！
Why, it's easy─a child could do it!
嗨，这容易得很，连小孩子都干得了！
3、作为名词，意为原因;理由;说明;难解的问题。
例句：He still could not throw any further light on why the elevator could have become jammed...
对于电梯为什么会卡住他仍旧给不出更多的解释。
'Want to spend the afternoon with me?' — 'Why not?'...
“想和我共度这个下午吗？”——“好啊！”
二、because的含义及用法
because作为连词，意为因为。
例句：I did it because he told me to.
是他吩咐我才做的。
Many families break up because of a lack of money...
许多家庭由于缺钱而破裂。
Just because it has a good tune does not mean it is great music...
仅凭旋律优美并不见得就是一首杰出的音乐作品。
We couldn't understand them because they were talking in Chinese.
我们听不懂他们在讲些什么，因为他们说的是汉语。
