There’s nothing wrong with explicitly telling your puppy ?no,? only that it often fails to offer enough information. Instead, you can tell him what you want. Dogs don’t usually generalize well, so if the dog jumps on someone in excitement and you say ?no,? he may jump higher or change direction. A better alternative would be to instruct him to sit. Telling him what you want helps to avoid confusion.
Focus on simple commands. Your puppy doesn?t understand English, and when you say, ?Sit down, Fido!? ?I want you to sit!? or ?Come on, sit!? all he hears is a jumble of confusing words. Repeating the word ?sit? will help your puppy associate that sound with the desired behavior. Use a single word instead of a sentence or phrase, and use that word consistently.