That's one of the reasons my most frequent verbalization in practice is "NO!"Excaliber wrote:"Don't move" is a much better initial command (you'll soon realize you can't continue to just look at each other and you'll have to give a series of directions after that) because it's unambiguous and close enough to the same phrase in Spanish that it's almost always understood. That's a major consideration in Texas and many other areas of the country as well.
I may say other things depending on the totality of the situation in the scenario practiced but the most common is a simple "NO!" with or without a stop gesture with my support hand, depending on the distance. The voice tone and body language are enough to make myself clear to dogs, so humans have no excuse.