The Polish guy was dead on -- it's much better to see the documentation (or any literature on software for that matter, languages, algorithms, manuals, etc etc) in English which is either the author's native language or a language he knows very well.
There's so much terminology in English and growing that outright sounds ridiculous in other languages due to inadequate or not generally accepted translations. And then a spanglish communication like that with plenty of borrowed English words here and there is ridiculous itself... Why not just use English for the whole thing, not just technical terms and use the language of the problem/industry?
Also, there's so much literature in English in existence (which also keeps growing) that it's just impossible to keep up translating everything. Likewise the amount of translated books (along with the quality of their translation) and books originally written in other languages is rather disappointing. And the same can be said about the programming information available on non-English websites. All of this pushes a non-native speaker of English (or should I say a non-speaker of English? to improve their English (or learn) and abandon the hopes of getting quality info in the right quantity in the native language.
I wish it was easy (just as easy as in the US) to go to a bookstore somewhere in Russia and see technical and any kinds of books in English, untranslated (maybe even at about the original price, undiscounted, although $50-$100+ for a book is pretty darn expensive in Russia) and be able to buy them. Some classic books take longer to get translated than it takes for a kid to grow up, graduate from the school, complete the master degree program and learn some good English.
Btw, just using lots of software in English, reading lots of docs in English and communicating in English really does improve the language skills. In that same Russia English instruction has been pathetic for decades and you may still reasonably expect pretty much anybody who's gone through 7 years of English at school+uni there to not know much if any English (what a shame!). Except the few who early on found something interesting in the language or just used it a lot, those like us, programmers.