I was wondering, in a sentence such as
Das Haustier ist ein Hund
would ein Hund be nominative or accusative (making it einen)? It seems like it should be accusative because it answers the questions of "is what?", but I feel like one of my teachers once said something about sentences like this being accusative. Other examples would be:
Mittens ist eine Katze, etc.
(even though there it would be eine either way) Thanks!