My English isn't perfect, it is actually far from good. But as long as people understand me, I fine with it. And I really like speaking English.
i think that is the main concern, as long as you can speak english well enough for people to be able to understand what you are saying, there is no problem what so ever. To much time spent on learning all the tenses, grammar etc etc is wasted in Polish schools, how about just learning simple conversations then expanding on them, after all the Poles who speak the best English i have found are those who have not been pressed through your schooling system but those who have learnt on arrival to the UK.
I find on average that Poles either speak great English or hardly any English at all. This i due to the fact a lot of Poles come to the UK and only talk and associate with the Polish. THose who speak good English are those who mix with the indigenous population. I really think it is that simple, if you come over to the UK and mix with native speakers you will pick up the language much quicker than if you only associate with Poles, not only that, you will also pick up everyday language which is not taught in the schools in Poland. To communicate on a day to day basis is more than having to learn all the tenses. What good is knowing all the tenses if you can't fit the words to make relevant senteences for the conversation that you are having.