写英语道歉信时，要注意以下几个要点：

表达歉意

开头要直接表达你的歉意，例如：“Dear [Recipient's Name], I am writing to express my sincere apologies for [specific incident].”

说明原因

简要、诚实地说明导致需要道歉的原因，不需要过多细节，可以使用抽象词汇概括，例如：“I regret to inform you that I was unable to attend your class due to unforeseen circumstances.”

提出补救措施

如果可能，提出具体的补救措施，显示你愿意承担责任并尽力弥补，例如：“I would like to make it up to you by [specific action].”

再次致歉

在结尾部分再次表示歉意，并请求对方的原谅，例如：“Please accept my heartfelt apology and allow me to make amends.”

保持礼貌和尊重

整个道歉信应保持礼貌和尊重的语气，避免使用任何可能被视为冒犯或轻视的词汇。

```

Dear [Recipient's Name],

I am writing to express my sincere apologies for missing your class last Thursday. I had a prior commitment that I could not avoid, and I deeply regret any inconvenience this may have caused you.

I understand that my absence disrupted the flow of your lecture, and for that, I am truly sorry. I value your class and the knowledge you impart, and I am committed to making up for this missed opportunity. If there is any way I can compensate for my absence, please let me know.

Once again, please accept my sincere apologies. I hope to regain your trust and continue to benefit from your teachings.

Yours sincerely,

[Your Name]

```

请根据具体情境调整上述模板中的内容，确保道歉信真实反映你的情感和态度。