I'm having an issue with this actually because my kid is in her terrible twos and she's also very stubborn and doesn't yet speak. I dont know if she understands me most of the time. I know she understands the word "NO!" but she doesn't always react by stopping what she's doing. In which case I smack her bottom even though I think it hurts me more than it hurts her. I am reluctant to hit her at all since she will hit herself afterwards and I find that very disturbing.