1. I'm (so / very / terribly) sorry.
（我很抱歉）
We use 'so', 'very' and 'terribly' to make the meaning stronger. 'Terribly' is the strongest. If we use one of the words in brackets, it is stressed.
2. Ever so sorry.
（实在对不起）
This phrase is quite formal but it's a stronger apology than just 'sorry'.
3. How stupid / careless / thoughtless of me.
（我真是太愚钝 / 粗心 / 轻率了）
Use this phrase to criticise ourselves, and the mistake that we have just made.
4. It's my fault.
（是我错了）
Sorry. That was all my fault.
5. Please excuse my (ignorance)
（请原谅我的……）
We use this phrase to apologise for our lack of knowledge or ability. We can replace the word in brackets with other nouns, e.g. carelessness, forgetfulness.
6. Please don't be mad at me.
（是我不好，你别生气）
Is asking the other person not to get angry. The tone is quite informal.
7. Please accept our (sincerest) apologies.
（请接受我们的诚挚歉意）
This is often used in formal letters. The word 'sincerest' makes the apology very strong and very formal.
