I have a 16 week old puppy and I’m following Hillman’s puppy video. He knows sit so I’m trying to reinforce it with a verbal “sit” and lifting up on the rope. When I do that he barks, bites the rope, then rolls over on his back and the lesson is lost. I’m not jerking on the rope - just lifting up on it. He’s been wearing a collar and dragging a rope since he was 8 weeks old so the rope and collar are not new to him. I realize he’s just a baby so I’m not being hard on him but rather trying to teach him what I want him to do. Is there something else I should try to reinforce the sit command or just stick with it until he figures it out?