I'm sorry to hear that.

听到这事我很难过。

I'm sorry about that.

我对此感到难过。

What a pity/shame.

太遗憾了！

That's unfortunate.

真不走运!

It must be tough for you.

那你肯定很难受吧。

It must be hard on you.

你一定很难过。

I know how you feel.

我理解你的心情。

I really sympathize with you.

我真的同情你。

How sad.

太让人伤心了!

It's a common mistake.

这是常见的错误。