anything和something的區別是什麼意思

例句：

Can you smell something burning?

你有沒有聞到什麼東西燒焦了？

Would you like something to eat?

你想吃點什麼嗎？

Do you have anything to declare?

你有什麼要申報的嗎？

They'll eat almost anything.

他們幾乎什麼都吃。

I overreact to anything sad.

我對任何悲傷的事情都反應過激。