iPandaapast tense: I would like to apologize to you for not attending Speaking Club xxx (kapan kamu nggak masuk? yesterday? two days ago?) without any prior notification to you. Actually, I was having xxx (kenapa kamu gak masuk? sick? family matter?), so I could not attend the club. I hope my apology letter will be granted and I do promise not to repeat this in future thank you.
Sincerely, (namamu)
future tense: I would like to apologize to you because I can't attend Speaking Club xxx (kapan kamu niat nggak masuk? tomorrow? this weekend?). Actually, I'll be having xxx (kenapa kamu gak masuk? sick? family matter?), so I can't attend the club. I hope my apology letter will be granted and I do promise not to repeat this in future thank you.
I would like to apologize to you for not attending Speaking Club xxx (kapan kamu nggak masuk? yesterday? two days ago?) without any prior notification to you. Actually, I was having xxx (kenapa kamu gak masuk? sick? family matter?), so I could not attend the club. I hope my apology letter will be granted and I do promise not to repeat this in future thank you.
Sincerely,
(namamu)
future tense:
I would like to apologize to you because I can't attend Speaking Club xxx (kapan kamu niat nggak masuk? tomorrow? this weekend?). Actually, I'll be having xxx (kenapa kamu gak masuk? sick? family matter?), so I can't attend the club. I hope my apology letter will be granted and I do promise not to repeat this in future thank you.
Sincerely,
(namamu)