在生活中，有時候我們要寫到道歉信，對我們的一些過失表示愧疚和悔過，那么各種理由的道歉信用英文如何表達呢?下面讓小編帶大家學習一下吧!

　道歉理由一：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,

　　CNrencai

　　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。

道歉理由二：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,

　　CNrencai

　　親愛的戴維：

　　請原諒我收到您12月7日的來信后遲遲未復，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臺上，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。