"Za" has quite numerous meanings. Let's see some of them:
za (+ instrumental) behind (denotes location) -> Za domem jest basen (Behind the house there's a swimming pool)
za (+ accusative) behind (denotes movement) -> Poszliśmy za dom (We went behind the house)
za (+ accusative) after/in a (?) (something will happen after a certain period of time) --> za minutę/za godzinę/za miesiąc (in a minute/hour/month)
za (+ accusative) in, for -> I don't know what about this 'in', but this has to be your example: Dziękuję za książki (Thank you for the books); Nienawidzę cię za to co zrobiłeś (I hate you for what you've done), etc.
Thank you for replying. However, there are a few occasions under other threads where an emphasis is placed on the subject of the sentence - and so answers where the subject of the sentence is misplaced would not be considered correct. This has also led me to think that subjects of sentences are more important in Polish (including everyday use) than in English?
With such Polish sentences, sometimes we put a literal translation as the main English translation (Behind the house there is a swimming pool) and sometimes we put the actual natural one (There is a swimming pool behind the house). We want to get people accustomed to the Polish word order but also show that you can't really translate "There is..." into Polish with an equivalent word order, such Polish sentences start with the location. So in English you are generally shown both constructions.
As for the subjects... I have to say that I don't see how a subject could be more important in one language than in another, they're generally crucial almost all the time.
Well... maybe dictionary? :) "House - a building for human habitation, especially one that consists of a ground floor and one or more upper storeys.". I understand that you probably imply that building is rather translated as "budynek", however I still believe it's a viable answer. Anyway - it's up to you guys.