I found this one difficult for a while. We were at work. I announced to my workmates that it was break time. 'Przerwa.' The response: 'No.' Okay then, you keep working, but I'm going for a cup of tea.
Nice to see the K-word has been given a mention too.
I have problems with "Yeah" sometimes I say it so fast it sounds like "Nie" and I get some funny looks :)
Want a wódka party tonight? Yeah! Nie kurwa? Nie, Nie, Yeah, Kurwa O spoko