Dear Joanne,
I'm writing to you because I'm appalled at your son's behaviour.
Last week I called round you but I didn't find you {AT HOME}. I knocked to {ON THE} door but anyone didn't open me {BUT NOBODY OPENED/ THERE WAS NOBODY HOME} . When I pushed the handle, the door opened. I was surprised and I had a premonition that something is {WAS} wrong. I entranced to {ENTERED, bez to} your house but I didn't {COULDN'T} see anyone. When I went {bez: to} upstairs{,} I heard {bez: a, music to rzeczownik niepoliczalny} music. I realized that someone was in your house. I thoughT about your son but I rememberEd that he should have been on {WAS SUPPOSED TO BE AT HIS} private lessons. I decided to go to your son's room. When I opened the door I was surprised. You can't imagine a {THE} situation which I saw. Your son and his two friends were drinking {a - to by bylo jedno, zapewne pili wiecej, wiec bez "a"} beer! Nevertheless {to slowo niezbyt pasuje, moze lepiej: AND YET}, he is {ONLY} 13 years old! I didn't know what I should have said {WHAT TO SAY} in this situation. Your son shouted at me, {ASKED} why I entered to house if anyone didn't open {NO-ONE OPENED}the door. He said that I'm {I WAS A} stupid woman and said{bez przecinka} {THAT} if I tell {TOLD} you something about this situation, he and his friends {WOULD} find me... He threatenED me with this words. He had never before been impolite. It was very unpleasant for me and I don't {WILL NEVER} forget about it.
I hope that you {WILL} talk with {TO!} your son because his behaviour was indecent {nie wiem, czy indecent jest tu najtrafniejszym slowem. Moze UNNACCEPTABLE?}.
Love,
Belinda