在生活中，有时候我们要写到道歉信，对我们的一些过失表示愧疚和悔过，那么各种理由的道歉信用英文如何表达呢?下面让小编带大家学习一下吧!

　道歉理由一：因未能践约赴宴致歉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,

　　CNrencai

　　亲爱的南希小姐：

　　小儿上周六突然生病，因此未能应约赴生日宴，殊觉抱歉，希原谅，再见。

道歉理由二：因迟复来信致歉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,

　　CNrencai

　　亲爱的戴维：

　　请原谅我收到您12月7日的来信后迟迟未复，现将原因告诉您，相信您一定会谅解的。您的来信到来时，我正巧在香港，家人无法及时转递。你的信一直放在我写字台上，直到我回到才看见，拖至今天才回信，深表歉意。

　　这次出去旅行饱览了许多美丽景色，下次见到您时，将告诉您一切。