You teach your dog to sit with positive reinforcement. First start by training him in a quiet place without distractions to maximize his attention. Stand in front of your dog. Place a treat in front of his nose to get his attention, then slowly move it upwards (over his head) so he sits naturally. Don't put the treat too high too quickly, or he may jump to get it instead of sitting. Accompany the gesture with your word “sit”. Once his butt touches the ground, give him the treat immediately.