1. I regret doing that.
我很后悔那樣做。
2. I am ashamed of ...
我對...感到很羞愧。
3. I shouldn't have done it.
我真不該那樣做。
4. If only I...
要是...就好了。
5. I should have asked you.
我要是問你就好了。
6. I went a bit too far.
我做得有點太過分了。
7. It was too careless of me to make such a decision.
我做這樣的決定太草率了。