something通常用于肯定句，anything通常用于否定句或疑问句。
例如：
There is something in the box. （肯定句）
There isn’t anything in the box. (否定句)
Is there anything in the box? (疑问句)
Nothing 在意义上等于 not anything。
例如： I know nothing about it. (=I don’t know anything about it ）我对此事一无所知。
everything :
1.一切事物；每样事物：
This shop sells everything needed for camping. 这家商店出售一切露营用具。
Tell me everything about it. 告诉我这件事情的始末。
2. 最重要的事；
Money is everything to him.金钱对他比什么都重要。
She`s beautiful,I gree,but beauty is not everything.我同意她是美丽的，但美并不是最重要的。
