Imagine, your friend borrowed one of your important books. Your exam is near. So, you need the book badly. Now, write an e-mail to your friend asking him to return the book immediately.

(Informal E-mail)

To: sabiha@yahoo.com
Cc:
Bcc:
Subject: Please, return the book
Sabiha,
Friend, you know that my annual exam is knocking at the door. So, I've to study more and more. You borrowed a book from me last month. This book is very important for both of us. I think you've already used it. At this moment, I'm studying a topic related to this book. So, I need this book badly. I hope you'll return this book as soon as possible.
All the best
Jaba
Sifot/Shila