Dear Susan{,}
I found a cat last week. {ciekawy ten poczatek, do rzeczy i na temat. ;-) Moglabys chociaz spytac, co slychac u kolezanki? Ale tak tez jest OK}
I found it when I was walking in the park. I go {WAS GOING/ WALKING } {bez:to!!} home from school. I took him home because he is {WAS - opowiadasz historie} beatiful{bez przecinka} and It {it} looked very sad.
My sister was really happy that we have a cat. Unfortunately, my parents don't like animalS and they are{czas przeszly?} not happy when I bring{czas przeszly??} {bez: to!!} {SZYK: 2-home} {1-this cat}. Now, when this cat live {lepiej: HAS BEEN LIVING} with us already {FOR} nearly {A} week, they'VE got used to him and acceptED him {HIS!!} presence in {AT!!} home.
The cat didn't want {TO} eat and he had some insects {zle slowo, lepiej: FLEAS - jesli o pchlach mowa}}, so I took him to a veterinary surgeon and bought {A}special collar and shampoo.
I must {brakuje czasownika, poza tym czas: forma przeszla od "must" to "HAD TO" + DO WHAT??} earlier because I must to {HAD TO} give eat to him {GIVE HIM FOOD albo FEED HIM}. I have to clean {bez:the} him{HIS!!!} cage.
That was {lepiej: IT IS} because of him {THAT} I have less free time but I am really happy that he have {happy THAT I HAVE HIM albo happy TO HAVE HIM}.
Take care.
XYZ