i am terribly sorry to tell you that i have lost the valuable book you were so kind to lend me last week. i read it everyday and intended to finish it next month. last night when i came to my room, it was nowhere to be found. i will try to recover it as soon as possible. if i fail to find it, i will get a new book for you.
but i am afraid it can never take the place of the old one. old books are like old friends. once lost, they can never be replaced. they are connected with cherished associations which the new ones can never have. and for this irrecoverable loss, i am to blame. i was so careless with my things. this is a warning to me to be more careful in the future.
thank you for your invitation to dinner at your home tomorrow evening. unfortunately, it is much to my regret that i cannot join you and your family, because i will be fully occupied then for an important exam coming the day after tomorrow. i feel terribly sorry for missing the chance of such a happy get-together, and i hope that all of you enjoy a good time. is it possible for you and me to have a private meeting afterward? if so, please don't hesitate to drop me a line about your preferable date. i do long for a pleasant chat with you.
please allow me to say sorry again.
dear prof. patent,
i am very sorry to inform you that i did not manage to complete the book report you assigned last week, due to a sudden illness falling upon me a few days ago. for the past few days i have been in hospital with a continuous fever, which has thus prevented me from any academic activity. i hereby submit the doctor's note.
i would be very much obliged if you could grant me another week for the task, as my health is turning better.
hope you can understand my situation and accept my apology.