Luke does thing incredibly cute thing where he says to himself, "no, no, no" when he's doing something he shouldn't be doing.
For instance, he may climb up on the kitchen chair and say, "no, no, no."
While taking my Blackberry out of my purse, I'll hear him say, "no, no, no."
"No, no, no" as he dunks his hands into Tank's water bowl.
It is great that he is beginning to understand the difference between appropriate behavior and some things that he possibly shouldn't be doing, but saying "no, no, no" while he does those things isn't going to make it any better -- even if it is cute. Just another thing to work on!