Thanks so much ALEXX and Zaya, for the examples..
Really helpful for me! I think examples are the best way to learn... What a pity that there is no easy answer...
@bitpicker: thanks for the explanation! English isn't my mothertongue and it feels like an irritating "detour" and distraction when learning Russian. I try to stick with Swedish material but it's not easy since I live in the UK. I speak English like a native and I don't normally make grammatical mistakes. But that's because I've had so much exposure, and not because I actually understand English grammar very well....
I've downloaded a bunch of Russian - English grammar books (despite my reluctance to using English in my Russian studies). Unfortunately there is some kind of hold-up with my Swedish Russian grammar books that I ordered from an online retailer. I hold up my hopes that when these books finally arrive all will become clear.. (never use bokus.com, what a bunch of clowns!)
I noticed you're German, or?? Are you using German or English material in your Russian studies? Do you feel that it matters or not?