'On' (lepiej During) my last holiday I visitEd my brother in Poznań. He 'was' (HAD BEEN) studying there for three years. 'I'm' (to znaczy teraz czy wtedy? bo jak wtedy to stayed) staying at my brothers flat. I have never been 'in' (TO) Poznań before....WarsAw.
There 'live' (ARE) about 600 'thousands' (bez s'- thousand) people )LIVING THERE AND lots of them are students.
I went 'for' (bez 'for') shopping to Stary Browar with friends of my brother. They 'showed me also' (also showed me) THE Plaza Centrum. It's 'a' (dlaczego 'a'?) similar to 'Stary Browar' (niewiem, czy mozna tez by bylo OLD BREWERY) emporium.
The most interesting for me was THE 'Stary rynek' (mozna napisac THE OLD MARKET). 'Monumentals tenements' (nie rozumiem, czy mowisz o momuments i osobno o tenaments czy o monumental tenaments?), guildhall, lot of caféS (chyba wiecej jak jedna, lots of daje znac ze to l. mnoga), pubs. It's a great meeting place 'with' (jabym tutaj dala 'for') friends.
My brother took me to the cinema, near by Stary Browar 'and on skates' (moze lepiej ...and also skating)
I 'have' (po co have?) stayed there for 'a' (dlaczego 'a'?) two weeks and I've never had such an enjoyable time in my life. The days that I
spenT in Poznań were excellent.