Regarding (English as) the international language ...
Last time I flew to the UK I had to concentrate to fully understand British English. For a non-english native speaker different dialects matter more than one would think (England, Scotland, Ireland, New Yawk etc.) . But it is not only English; it took me longer than expected to flawlessly understand Canadian ATC
en francais . Y espanol? Forget it, when you fly over Cuba. I need to talk to them in English.
I know I am missing the point here a bit
, but I thought it was worth bringing it up.