因過失或疏忽做錯了事，給別人帶來了麻煩或損失，發覺後要立即寫信給對方賠禮道歉，這是一種禮貌。道歉信要寫得坦率，誠懇。
1、因未能踐約赴宴致歉unable to keep one's promise
dear miss nancy,
much to my regret i was unable to keep my promise to attend your birthday party last saturday, owing to the fact that my little son was suddenly taken ill early that day.
hoping to see you soon.
truly yours,
tom
親愛的南希小姐：
小兒上周六突然生病，因此未能應約赴生日宴，殊覺抱歉，希原諒，再見。
2、因遲復來信致歉because of answering one's letter late
dear david:
i am afraid that you will think me unpardonably negligent in not having answered your letter dated 7, december sooner, but when i have told you the reason, i trust you will be convinced that the neglect was excusable. when your letter arrived, i was just in hong kong. as my family could not forward it to me during my absence, it has been, therefore, lying on my desk until the moment when i took it up. now the first thing i have to hasten to do is to write to you these few lines to express my deep regret.
i enjoyed many pleasant sights during my trip. i shall be pleased to give you an account to of them when i see you next.
sincerely yours,
tom
親愛的戴維：
請原諒我收到您12月7日的來信後遲遲未復，現將原因告訴您，相信您一定會諒解的。您的來信到來時，我正巧在香港，家人無法及時轉遞。你的信一直放在我寫字檯上，直到我回到才看見，拖至今天才回信，深表歉意。
這次出去旅行飽覽了許多美麗景色，下次見到您時，將告訴您一切。
3、因未能及時還書致歉unable to return borrowed book on time
dear kate:
excuse me for my long delaying in returning to you your “robinson crusoe” which i read through with great interest. i had finished reading the book and was about to return it when my cousin came to see me. never having seen the book, she was so interested in it that i had to retain it longer. however, i hope that in view of the additional delight thus afforded by your book, you will overlook my negligence in not returning it sooner.
thanking you again for the loan.
sincerely yours,
tom
親愛的凱特：
我遲遲未能歸還您的那本《魯濱遜飄流記》，請原諒。該書我讀得津津有味。讀完後，正預備歸還您時，我的表妹來訪，見這本書也感興趣，定要借去一讀。為了讓別人也能分享您那本書所給予的樂趣，我不能及時歸還。我想再延遲些日子奉還，諒您不會介意的。
再次感謝您的慷慨。
4、因遺失借書致歉because of losing a borrowed book
dear frank:
i am terribly sorry to tell you that i have lost the valuable book you were so kind to lend me last week. i read it everyday and intended to finish it next month. last night when i came to my room, it was nowhere to be found. i will try to recover it as soon as possible. if i fail to find it, i will get a new book for you.