Quentin has started nodding sometimes to say yes. Especially when you ask him if he likes music. He usually makes a happy/excited sort of laughing noise when he wants to say yes. He has no problem saying the word no though. He definitely knows what he wants and makes himself understood either way.
Quentin has also started pretending. He fed me some pretend food from a plastic Easter egg, which was new. He loves feeding himself and will have food all over himself with no complaint, but if he gets a drop of yogurt on his fingers he freaks out until I wipe it off.