● 后悔

我真不该那样。
I shouldn't have done it. *用“shouldn't have+过去分词”表示类似责备或斥责的心情,“不该……”、“要是没……”。
Oh, no! I shouldn't have done it. (哦,不!我要是不那样就好了。)
What did you do? (你干什么了?)
That was a mistake. (那是一个错误。)
I blew it. (我失败了。)
I wish I hadn't done that.
I really screwed up this time. (这次我真的给弄糟了。)
I really messed up. (我给搞糟了。)
I should have known better. (我早该弄清楚一些。)

我要是不说那话就好了。
I shouldn't have said that. *用于说了不该说的话时。
I shouldn't have said that. (我要是不说那话就好了。)
It's too late now. (现在后悔也晚了。)
I wish I wouldn't have said that.

我早该知道了。
I should have known.
He's married. (他已经结婚了。)
I should have known. (我早该知道了。)
I acted like a fool.
I should have known better. (我早该弄清楚了。)

做那种事,我也太不小心了。
It was careless of me to do so. *careless 表示“没注意的”、“漫不经心的”、“粗心大意的”。
It was thoughtless of me to do such a thing.
It was hasty of me to do so.
I was careless. (我太粗心大意了。)

我后悔我做的事。
I regret doing that.
I regret doing that. (我后悔我做的事。)
I know what you mean. (我明白你的意思。)
I regret my action(s).
I repent my action(s).
I am sorry for what I have done.

我别无选择。
I had no choice.
Why did you drive my car? (你为什么开我的车?)
I had no choice. (我别无他法。)
I couldn't help it.
I had no other choice.
I had no choice in the matter.
There was nothing else I couldn't have done.
It was my only choice.

我做得太过了。
I went too far. *比较常用的固定短语。
You shouldn't have done that. (你不该那样做。)
I know, I went too far. (我知道,我做得太过分了。)
I overdid it.

我太紧张了。
I was too nervous. *也可用来辩解。
Did you ask her out? (你约她了吗?)
No, I was too nervous. (没有,我太紧张了。)
I was too uptight.

我要是再用功点就好了。
I wish I had studied harder.
I regret not studying harder. (我后悔没有更努力学习。)
I should have studied harder.

我要是问他一下就好了。
I should have asked him.
I should have asked him. (我要是问他一下就好了。)
Why didn't you? (那你为什么不问呢?)
I wish I had asked him.
It would have been better to have asked him.

不留神给忘了。
It slipped my mind.
Did you remember to tell her? (你没忘了告诉她吧?)
Sorry, it slipped my mind. (对不起,我不小心给忘了。)
I just forgot.
I forgot all about it. (我忘得一干二净。)