anything和something的区别是什么意思

例句：

Can you smell something burning?

你有没有闻到什么东西烧焦了？

Would you like something to eat?

你想吃点什么吗？

Do you have anything to declare?

你有什么要申报的吗？

They'll eat almost anything.

他们几乎什么都吃。

I overreact to anything sad.

我对任何悲伤的事情都反应过激。