生日道歉信的结构和要点：

1. 开头： - 表达诚挚的歉意，例如：“Dear [对方名字], I'm extremely sorry.” 2. 解释原因： - 诚实地说明导致错过生日或造成不愉快的具体原因，如：“I had to deal with an unexpected emergency at work and couldn't be there for your birthday.” 3. 表达遗憾： - 强调对未能参与生日或给对方带来不好感受的遗憾，例如：“I feel so bad that I missed this special day for you.” 4. 弥补措施或承诺： - 提出补偿的方式或者承诺未来会做得更好，比如：“I promise to make it up to you. How about we celebrate together next weekend?” 5. 结尾： - 再次表达歉意和祝福，比如：“Once again, I'm sincerely sorry and hope you had a wonderful birthday despite my absence. Love you always.” 以下是一个简单的示例： Dear [Name], I'm extremely sorry that I wasn't able to be with you on your birthday. I had a last-minute business trip that I couldn't avoid. I feel so bad that I missed the chance to celebrate this important day with you. I know how much it means to have loved ones around on such a special occasion. To make up for it, I have planned a surprise for you. Let's get together this coming Friday and I'll do my best to make it a memorable day. Once again, I'm sincerely sorry and wish you all the happiness in the world. Love, [Your Name]