If you want to teach your dog a command you will have to tell him that he has shown the correct behaviour. That has to happen 1-2 seconds after his behaviour in order for him to make the connection and learn. Rewarding correct behaviour can be done with a clicker or your voice and a treat or a toy. When using positive reinforcement your dog will actually feel happy and remember those emotions when using that command in the future. That will help your dog to stay calm and trust you more. This can help you change any underlying negative feelings in your dog that can cause problem behaviour. Using force or pain on your dog may show short term results but it will not make your dog trust you and therefore won’t be obedient in stressful situations, he will only listen to you because he’s scared. Ideally you want to work with your dog and not against him.