The way you choose to say stop depends on the context. For example, you could say ‘cut it out’ if you want someone to stop doing something annoying. Or ‘hey Carlos, wait!’ if you want him to stop walking. Some general synonyms: finish, end, close. Hope this is helpful!

If your little brother is being a pest, you could say, "Knock it off!" If Carlos is walking ahead of you, and you want to catch up to him: "Hey Carlos, wait up!"

Stop what ? The alternate words or phrases will depend on this.