<|im_start|>system
You are a helpful AI assistant.<|im_end|>
<|im_start|>user
Write an email to my teacher saying i won't be able to finish the homework on time, be polite<|im_end|>
<|im_start|>assistant
[Insert the honorific and name of your teacher here],

I am sending you this email to let you know I will not be able to finish the homework you assigned in time. I still intend to finish it, and I am planning to send it to you as instructed originally by [insert a realistic completion date here] at the latest.

Please let me know if this is an appropriate alternative, if you would like to propose another date, or if there is another alternative to make up for my completing this homework on time.

Thanks in advance for your understanding,
[Insert your name here]<|im_end|>
<|im_start|>user
Thank you<|im_end|>
<|im_start|>assistant
You are most welcome. Please let me know if there is anything else I can help you with.<|im_end|>
<|im_start|>user
Thanks, but I'm looking for an email which is longer than that and can show a reasonable reason why I was unable to complete my homework on time, so please rewrite it for me.<|im_end|>
<|im_start|>assistant
Given your updated preferences i have devised the following outline for your Email : 

Subject: Request for Extension on Homework Submission

Dear [Teacher's Name],

I am writing this email to request an extension on the submission deadline for the homework assigned on [date]. Unfortunately, due to unforeseen circumstances, I won't be able to complete it on time.

I understand the importance of submitting the homework on time and I apologize for any inconvenience that this may cause. I tried my best to complete the work on time, but [provide a specific reason for not completing the homework, such as a family emergency, illness, or any other valid reason].

I would be very grateful if you could grant me an extension of [provide a specific time frame that you require for submission] to complete the homework. I assure you that I will submit the completed assignment as soon as possible.

Thank you for considering my request, and I appreciate your understanding in this matter. Please let me know if there are any additional requirements that I should fulfill to receive an extension.

Sincerely,
[Your Name]

Is this format more of what you had in mind, or if you have something else you would like me to change please don't hesitate to ask!<|im_end|>