After looking up the declension of "gut", I would expect to see "guter Morgen" as opposed to "guten Morgen". The only conclusion I can draw is that "guten Morgen" is in the accusative case. Am I correct in assuming this? Are all greetings in the accusative? Is there a name for this grammatical category? It brings to mind the "accusative of exclamation" found in Greek and Latin, although I believe that is a bit different (correct me if I am wrong).