It probably depends on the person, a normal person wouldn't probably mind. Me for instance, I would appreciate that someone is learning my pretty difficult language at all ;)
That would be the reaction that I found quite often as a native English speaker with minimal (at best) understanding of the Polish language during my stays there. In fact, I can't remember a single person being anything other than extremely friendly when I butchered their language.
I'm pretty sure that's how it work.. the only the that might spark a decline is when somebody wants information or your task being done quickly and can't do it due to the communication problem, same as problems with trying to explain something to Polish bus drivers in UK.
I too found the Poles whom I encountered, first of all, delighted to hear that a foreigner could "speak" their language, second of all, most helpful when making inquiries:-)
Don't recall being corrected much, except for many asking me to repeat my questions lol
The Dworzec Glowny in Szczecin was relatively close to our hotel. My friend though at the time, was a student of architecture in Berlin and was nagging me to take her to see the local City Hall, as she only knew German and I could translate for her a little.
Lyżko, it isn`t nice to abuse people in this way. Watch out, you can get a warning and lose decent posters` respect. And it doesn`t suit a teacher to use such vocabulary.