I'm writing to apologize for having forgotten to return the "the Beatles" CD to you when I left Canada,I was in such a hurry that I packed everything in my luggage without checking carefully.Had I paid more attention then,I wouldn't have made such a stupid mistake.
Now something must be done to solve the problem because I understand you cherish the CD enormously.I can either send it to you by express mail or alternatively compensate you at a reasonable price.If you do not mind,I may bring it back to you next time I go to Canada.
Please let me know which solution you prefer at your earliest convenience.I really hope you will accept my sincere apology.
I am terrible sorry for not having attended your class on time. Because I had got a headache for several days and it is my first time to live in Chongqing and I can not suit for the weather here quickly.
To be honestly, I like learning English very well and I have made my mind to learn it well both on spoken English and on written English. I think you will be my best teacher to help me improving my English Level. So I apologize again for my not attend your class. I will make my great effort on English in the future and will not make you disappointment next time!
Excuse me for my unintentional fault!
Thank you for your invitation to dinner at your home tomorrow evening. Unfortunately, it is much to my regret that I cannot join you and your family, because I will be fully occupied then for an important exam coming the day after tomorrow. I feel terribly sorry for missing the chance of such a happy get-together, and I hope that all of you enjoy a good time. Is it possible for you and me to have a private meeting afterward? If so, please don't hesitate to drop me a line about your preferable date. I do long for a pleasant chat with you.
Please allow me to say sorry again.