No I was talking about Polish shops outside of Poland.
Well, if they greet you with ' Dzień dobry', you could always return the greeting back! I think it depends how confident you feel with your Polish tbh.
I don't think if you spoke to them in Polish it would be odd, especially as you're learning. It's a good chance to practice your skills!
Still studying Catsoldier, although my Polish lodger has gone now:( Still practice with friends though.
There are 2 very good and recent threads on here by a poster called Kcharlie ' Polish language; basic concepts' and ' Polish in a nutshell'.
He explains the cases extremely well, so go to language section and have a look. definitely worth a read.