Reflecting about the Arab people and the way they relate with Arabic language, I came up with this question: Is there any possible set of circumstances that could have led to a similar diglossia within the Spanish speaking world? By that I strictly mean a situation in which, for exaple, an Argentinean and a Spaniard (or whatever the counterparts), use mutually unintelligible dialects of Spanish in their everyday lives, languages in their own right, while for public matters they use a prestige Modern Standard Castillian. Your thoughts?