not always.
i was in McDonalds the other day ordering a cheesburger combo. when she asked if i wanted coke i said no i wanted water. nam plow. as i pointed to the small fridge with water in it.
she looked at me all starry eyed. so i said nam ploooooooooooow and she was like ok perfect.
there is some validity in what other posters have said it cannot be brushed off. 10 plus years living here and i personally have many examples of interactions just like that. as do other posters.