Essential concepts to teach your toddler

As our little man is getting older (nearly two now !!!) I'm realising how important it is to get certain key concepts in life across to him. Not in a Baz Lurman "use sunscreen" kind of way ... but stuff that helps us communicate and prevents him from getting hurt. Here's what I've come up with so far:

1) STOP! or danger / dangerous
2) "Yes" / "No"
3) "Hot" / "Cold"
4) Where is ... or where does it hurt?
5) Day / night
6) Likes / dislikes
7) Directions (left / right / up / down / under / over / forward / backwards)
8) I need a pee / poo (hah ... I wish!)
9) Loud / quiet
10) How much? ... you're dreamin' (just kidding)

What did I forget?

-Stef