‘something’ ‘anything’ “everything”用法

‘something’ ‘anything’ “everything”用法
我知道“something”用于肯定句
“anything”用于否定句
可“something”不是“一些事”的意思吗
而“anything”是“任何事”的意思诶

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.