Pet language

I still feel like this is a stupid question but I really wanna know lol

see different cultures talking to their pets specifically dogs…. all of which are talking to them in their own respective languages. So my question is : Do dogs in America understand only English commands?
Dogs in South Americas understand only Spanish or French? Or they learn to understand the body language of their owners, to respond back accordingly regardless of where they are in the world? I have just become ever increasingly curious about these interactions.