Writing prompt: A Request of Mine

Student essay:
Dear Mr.Brown,
I'm L,an exchange student who accommodates at your home.I'm sorry to teii you a truth that i left my English dictionary.I hope that you could help me to send my dictionary back.
As far as I'm concerned,this is an important dictionary which is of great significance.It is a value dictionary which was a gift from my English teacher.She is a kind woman who comes from America.At the same time,when I came to America,she provided lots of help to me.when I had to come home,she send me a dictionary to encourage me to work hard.I'm appreciate it that she did me a favour.
I left my dictionary at my bookshelf in my bedroom.I could provided postage by myself.
Yours, L

Corrected essay:
Dear Mr. Brown,
I'm L, an exchange student who is accommodated at your home. I'm sorry to tell you the truth that I left my English dictionary. I hope that you can help me to send my dictionary back.
As far as I'm concerned, this is an important dictionary which is of great significance. It is a valuable dictionary which was a gift from my English teacher. She is a kind woman who comes from America. At the same time, when I came to America, she provided lots of help to me. When I had to come home, she sent me a dictionary to encourage me to work hard. I appreciate it in that she did me a favour.
I left my dictionary on the bookshelf in my bedroom. I could pay the postage by myself.
Yours, L