Most Northern English people pronounce "bus" with a different vowel from that used in Southern English (compare ovdje vs. ovde) and some Scottish people regularly use the word "bairns" for "children" (compare vlak vs. voz). When I lived in Northern England, I often pronounced "bus" in the Northern way, both consciously and unconsciously. If I lived in Scotland, and heard most people saying "bairns", I would probably end up saying "bairns" too. According to Wikipedia, 4.4% of the population of Croatia are Serbs, and in some parts of Serbia, there are a lot of Croats (10% in Subotica). I wonder whether these people also adapt their language, so that a Serb living in Croatia would ask about "vlak do Zagreba" at the railway station and a Croat living in Subotica would ask about "voz do Novog Sada"?