@ramax When I was learning English, I tried to play games in original English language with subtitles in mine to help me learn. I think that helped. That could be something to try, but you're right, at the beginning it does require concentration. It may help to start doing that in more laid-back games like puzzles or turn-based tactics where you can always take a pause. In more dynamic metroidivanias or shooters, it is harder.

But in my experience, this way you can speed it up quite a bit. Though everyone learns differently, of course.