We've been working on a new concept lately- the concept of "same and different." To practice, we've been playing a little game.
I made a set of picture cards out of halved index cards. I drew four simple pictures and made four copies of each. Then I shuffled the cards and turned over two cards in front of M and asked her what the pictures were.
I then asked her "Are they the same?"
If they were different, I would say, "No, they're different," and we would shake our heads sadly together.