Stop commands are one of the most common misunderstandings between dog and owners, because many people just assume that the dog understands a firm “NO!” without ever really teaching them what it actually means.
The fact that this command is used to control many different kinds of situations does not make it much easier for the dog.
Luckily in many situations our Bull Terriers or other dogs do understand the meaning over time.
Because after experiencing certain situations and the tone of the voice repeatedly they can eventually count one and one together and learn the meaning of “NO” on their own.