In the case of Italy, I would also doubt (as you do) that a hypothetical “North Italy” would choose anything other than Italian as its official language, because the use of Italian goes back a lot further than the unification of Italy, and it’s the obvious and easy choice as a national language. The government simply doesn’t care about the regional languages dying out, and there’s no reason to think that a new North Italian government would have a different viewpoint. The main motivation, in the case of Italy, was just to have everyone speaking the same language.
However, it’s certainly possible for a country and a population to completely change language in a generation. The Italian generation of people that is now about 60 years old are effectiviely bilingual—they were taught in Italian at school, but (generally) spoke their regional language at home. The generation after that spoke only Italian, and the generation before that spoke only the regional language. (Obviously this is a bit of a generalisation.) So it’s quite straightforward for a country to change it’s language over the course of 20 years or so.
I have a colleague in the Netherlands who believes that the Netherlands will at some point adopt English as its official language. I personally doubt it, but it is nevertheless definitely possible. All it would take is for the government to decree that all schoolchildren be taught in English at school. Dutch people (and particularly Dutch school-teachers, which is the important thing) would easily be able to carry that policy out. The first generation of schoolchildren to pass through to adulthoold would probably choose to speak in English as their primary language, as has happened in Italy.
Also Brussels has changed from a Flemish speaking city to a French speaking one in a short space of time.
However, it’s certainly possible for a country and a population to completely change language in a generation. The Italian generation of people that is now about 60 years old are effectiviely bilingual—they were taught in Italian at school, but (generally) spoke their regional language at home. The generation after that spoke only Italian, and the generation before that spoke only the regional language. (Obviously this is a bit of a generalisation.) So it’s quite straightforward for a country to change it’s language over the course of 20 years or so.
I have a colleague in the Netherlands who believes that the Netherlands will at some point adopt English as its official language. I personally doubt it, but it is nevertheless definitely possible. All it would take is for the government to decree that all schoolchildren be taught in English at school. Dutch people (and particularly Dutch school-teachers, which is the important thing) would easily be able to carry that policy out. The first generation of schoolchildren to pass through to adulthoold would probably choose to speak in English as their primary language, as has happened in Italy.
Also Brussels has changed from a Flemish speaking city to a French speaking one in a short space of time.