Write a letter to your friend asking him to return books.

Dear Nusrat Sharmin,

I hope this letter finds you well. It's been a while since we last talked. Our Annual/SSC exams are coming up, and I'm quite busy with my studies. I'm guessing you're also wrapped up in your studies. By the way, I wanted to remind you about a book you borrowed from me last month. I really need it now. It's an English grammar book. I know time flies, but it's been over a month. If you've forgotten, that's okay. I'm just hoping you could return it soon because I need it for my preparations. After the exams, if you still need it, I'll be happy to lend it to you again. I really hope you don't mind me asking about it.

That's all for today. Take care.

Warm regards,

Apnan Karim