接受你的辞呈，我感到非常遗憾。

It is with great regret that I accept your resignation.

很遗憾，我不能接受你的友好邀请。

I regret that I am unable to accept your kind invitation.

他遗憾地说：“恐怕不行。”

'I'm afraid not,' he said regretfully.

蒂姆的事让人遗憾，你说是不是？

It's a shame about Tim, isn't it?

你不能再多停留些时间，真是遗憾。

It's a pity that you can't stay longer.

遗憾的是没有早些报警。

It is regrettable that the police were not informed sooner.

我对前几天的那个问题感到非常遗憾。

I'm awfully sorry about that problem the other day.

很遗憾，我们无力改善目前的状况。

Unfortunately, there is nothing we can do to improve matters.

很遗憾，我们暂时脱销了。

I'm afraid we're temporarily out of stock.

宣布决定的方式非常令人遗憾。

The manner in which the decision was announced was extremely regrettable.

令人遗憾的是这一地区的犯罪率在不断上升。

Regrettably, crime has been increasing in this area.

很遗憾，他们的演出真不怎么样！

Their performance was fairly grim, I'm afraid!