You do not say, “Arret!” (French for “Stop!”) around our mastiff. All her formal commands are in French, and that’s her attack command. If you give it to her and there’s no obvious target around, she gets confused as hell and very tense.
We found this out by accident when my MIL, a Francophone, was down visiting from Montreal. I was going to pour her a cup of coffee and reached for a new cup. She yelled for me to stop, since she already had a cup out.
MIL: “Arret!”
The Dog, looking around frantically: “Who? Whoooooooooo?”