Dear sir
I am writing to offer my sincere apologies for borrow a book from your and I forget to return it on time scheduled on Monday morning.I deeply regret any inconveniences or disruption this may have caused to your plans.
The first thing which should be mentioned is that I could not finish reading this book due to some problems. I did not know it would happen like this. I am very sorry. Besides, I had work. I could not find any free time outside of my work. That’s why I did not complete studying the book.
Please accept may deepest apologies for my irresponsibilities. I take complete responsibility for my oversight and assure you that it will not happen again. In order to make amends I will definitely give you the book this weekend. If the book is significant for you , I can send it to your address right away and it should be reach you within a day.
I hope my apologies will be taken to into the consideration and look forward to receiving your response letter soon.
Yours faithfully
Sara
