regret的形容词
1、regretful后悔的，遗憾的；惋惜的
例句：We were deeply regretful to hear that you could not come and spend the vacation with us.听说你们不能来和我们共度假期，深感遗憾。
2、regrettable令人遗憾的；可惜的；可悲的；抱歉的
例句：It's everyone's dream to own a comfortable and no regretable life.我们每个人都希望能拥有舒适且无悔的一生。
regret的副词
1、regrettably遗憾地；抱歉地；可悲地
例句：Unfortunately,only a few people in modern society enjoy and appreciate classical music.遗憾的是在当代社会中只有少数人享受并欣赏这些古典音乐。
2、regretfully懊悔地，遗憾地；抱歉地
例句：He shook his head regretfully.他遗憾地摇摇头。
regret本身有动词和名词的词性
vt.后悔；对……感到遗憾；礼貌或正式地表示惋惜或抱歉；对（损失或缺乏）感到痛惜
vi.遗憾
n.遗憾，歉意
例句：
vt. I regret that you see it like that.你这样看待这件事,我很遗憾。
vi. Those who have not bought insurance are now regretting.那些没有买保险的人现在后悔了。
n. He felt no shame and no regret.他既不感到羞愧也不感到遗憾。