表达遗憾，最常用的句型：

句型1：
I wish I had done sth.
我希望我做了某事。
I wish I hadn't done sth.
我希望，我没有做某事。
I wish I had checked the weather this morning.
我要是今天早上看了天气就好了。
I wish I had done more exercises then.
我希望那时候，多运动就好了。
I wish I hadn't eaten so much.
我希望我没有吃那么多。

句型2：
If only I'd done sth.
我要是做了...就好了。
If only I had some role models.
我要是有好的榜样就好了。
If only I had shown myself strong in the face of temptation!
面对诱惑的时候，我要是更坚定一点就好了。

句型3：
I should have done sth.
我本应该做...
It was a great party last night. You should have come. Why didn't you?
昨天的聚会很棒。你没有，如果你来了你会很开心的。
I should have told you so.
我应该告诉你的。
I should have got a better price for the house, but I'm not much of a businessman.
那个房子我本来应该卖个更好的价钱的，但是我不大会做生意。

句型4：
I regret sth/doing sth.
我为某件事，感到后悔。
I bitterly regretted ever having mentioned it.
我非常后悔提起了那件事。
I deeply regret what I said.
我非常后悔我说了那些话。
I've had a wonderful life. I don't regret a thing.
我这一辈子都生活得很好，我没有什么遗憾。