On the politics and practicality of speaking like a local.
See, e.g. Swiss German.
I love the Max Weiner quote, “A language is a dialect with an army and a navy”. Singularly appropriate since he said it about Yiddish, which went on to be absorbed by Hebrew in the process of acquiring its army. I also like it as someone who lives in Switzerland, which has a whole lot of army and yet pretends to speak the language of its neighbours. Better buy a warship to sail about on Lake Constance is all I'm sayin'.
- Andrew McKenzie on why written and spoken French are so different: