Hal9009, Polish grammar is awful. don't use it. My wife is Polish and we were looking for something so I could learn. We also found it and it looked great. but as we got going, found it's loaded with errors. be careful
Hmm, as if Polish isn't difficult enough already! Actually, i've only looked at the tests on polish grammar to date.
Have you come across this web site?
polish.slavic.pitt.edu
It's the best free online resource that I've found yet. I use it's materials all the time.