regret的形容词令人惋惜的

This is more than regrettable; it is dangerous.

这不仅仅是令人感到遗憾的，更是危险的。

It is regrettable that you should make such a remark.

很可惜你竟然说这些话。

Yesterday is regrettable, tomorrow still hypothetical.

昨天已经逝去，明天还未到来。