I thought genitive was a possessive case, like "Der Kunst der Fuge" or "Der Meister des Welt". Or is that only in German?
The genitive is used much more often in Polish than in German. It's used for possessives like in German, but also for direct objects of negated verbs, among other things.
So... To sum up :
Subject verb complement
For the complement use the accusative
If verb = być use the instrumental
If subject = to and verb = być, use the nominative
If the verb is negative use the genitive
Is that right? :P
Yes … except that there are some verbs (eg, potrzebować (to need) or słuchać (to listen)) taking the genitive even in positive sentences (and in negative sentences as well), but you can’t really guess for which verbs it will be the case, you have to learn it whenever you meet such a verb.
Not to be a spoilsport, but it's "die Kunst". Unless it's in the genitive ;) Der Komponist der Kunst der Fuge ist mein Lieblingsmusiker aller Zeiten :D - my Polish isn't good enough to say that yet
„Kompozytor Sztuki Fugi jest moim ulubionym muzykiem wszech czasów„ — it's been so many years since I had German at school and I hated these classes back then, but hopefully I got everything right.
Why not 'Can you not see the dog?' ? The hint suggests widzisz can mean 'see' or 'can see' so I would have thought 'Can you not see..' would be accepted.
I would have thought it should be accepted, not because of something in Polish, but because English has the curious habit of saying "Can you see/hear/sense X" where many other languages tend to use "Do you see/etc X", while using "can" sounds more emphatic in them, kind of like "Are you able to see/etc X".
Just a thought.