Fellow Aviators,
How is this issue any different from a foreign language being spoken in that country's native tongue? When I fly in China I here Chineese being spoken, French in france, Africanz in south Africa.
If you address a contoller in the propper vernacular, you should be replied to in the same. As a habit, when outside the US I repeat ATC instructions verbatim. I routinely ask the people I fly with to avoid the colloquialisms of the US, as they are often met with a repeat of the ATC transmision (or Silence). In some countries the only engilsh the ATC personnel speak are the words required to be spoken and their meanings, nothing else.
It has been my experience that some of the things done outside the US could help inside the US and vive verse.