关于regret的翻译

今天上课翻译单选题，翻译到regret时遇到有趣现象。regret意为遗憾，后悔。那若把regret　to　do译为后悔去做某事，那它和regret　doing后悔做过，都表示做过某事了；若regret　to　do译为遗憾没去做某事，那regret　not　to　do也译为遗憾没去做。绕了一节课没绕出来，我能分清它们的用法，就是这个翻译挺有趣，有高手给解答一下。

regret：n. 遗憾；抱歉；悲叹

vt. 后悔；惋惜；哀悼

vi. 感到后悔；感到抱歉

regret to do：对要做的事遗憾

对将要做的事表示遗憾

但我实在没办法

regret not to do：后悔没有做

请不要遗憾 你也曾拥有拥抱的温暖 再难忘的话语 再难忘的脸庞 也会被时间冲淡 抱怨为赘言 眼泪为徒劳 往事不可留 逝者不可追 余音绕梁 无语凝噎 逝者如斯 不舍昼夜 歌声缥缈 只为你我 漫漫长夜 心已成节 请不要不舍 你无力篡改已定的历史 (再难寻的幸福) 再难守的秘密 也能够找到出口 抱怨为赘言 眼泪为徒劳 往事不可留 逝者不可追 抱怨为赘言 眼泪为徒劳 往事不可留 逝者不可追 余音绕梁 无语凝噎 逝者如斯 不舍昼夜 抱怨为赘言 眼泪为徒劳 往事不可留 逝者不可追 歌声缥缈 只为你我 漫漫长夜 心已成节 you don't regret your past embraces time will forget phrases and faces no more saying words no more crying tears all that was before is no longer here no more singing songs silent lips are dry all that was before slowly passing by no more singing songs just for you and i silent nights are long broken hearts are dry no turning back no cancellation cat's in the bag train's at the station no more saying words no more crying tears all that was before is no longer here no more saying words no more crying tears all that was before is no longer here no more singing songs silent lips are dry all that was before slowly passing by no more saying words no more crying tears all that was before is no longer here no more singing songs just for you and i silent nights are long broken hearts are dry

regret to do 的用法是（在正式的信函或声明中）对于要说的某事很遗憾或感到抱歉，一般不用在过去时。regret doing soomething 是对已发生的赶到后悔或遗憾。

regret to do因为要做某事而感到遗憾/抱歉 regret doing对已做过的事情遗憾/抱歉，宁肯当时没有做过