Practice this many times. It may take 10 times before your dog understands! When you think he knows the word "Sit", try it without the treat. If he doesn't sit, don't say anything. Just try it with a treat again. Praise him whenever he does what he is supposed to do.
You can teach your dog to sit while he is by your side, facing you, or while you are walking him on a leash. Repeat the steps above in many different positions and places. Once your dog knows what "sit" means, he will be happy to please you.
TIP:
When you give the command to "Sit", say it only once. Don't repeat
it because your dog will learn that he doesn't have to sit the first time. If
he doesn't sit the first time, just go back to practicing with the treat again.
Don't forget to say "good boy" whenever he is working hard!
You should never punish your dog or yell at him if he doesn't sit. He is doing nothing wrong. He is just learning.