On a course quiz of mine in an introductory-level German class, we had the following question about correctly identifying the accusative case:
What confuses me is that this question doesn't seem grammatically correct. Why does it say "auf den Schreibtisch"? Should that not be "auf dem Schreibtisch", the dative form of a masculine noun?
German expresses the same thing that English distinguishes between in and into (or on and onto, as in your case) with accusative and dative case.
In case your sentence describes a movement of an object to somewhere, the object is in accusative, if it describes the (more or less) static location of the object, the object has to be in dative.
So,
Ich stelle den Computer auf den Schreibtisch
denotes a movement, thus accusative, while
Der Computer steht auf dem Schreibtisch
describes a static location, thus dative - Your text book is correct.
With Akkusativ and the word "stellen" (which implies that something is done to an object, not that object is doing something actively) you indicate where are you placing an object, whereas Dativ is used to state where the object is. "Stellst du Computer auf dem Tisch" is grammatically wrong.
So "stellst du den Computer auf den Tisch" means "will you place the PC on the table". Whereas "der Computer ist auf dem Tisch" means "the PC is on the table"
