The Role of Language in Multilingual Con-Worlds

The US technically has no official language, but the working language of government has been English always. And it varies from state to state, how much that's enforced and how much other languages are recognized. There might be a difference between the use of Amhark and Ethiopia compared to Swahili and Kenya based on Ethiopia's empire using Amhark versus Swahili as kind of a trade language. In Switzerland, it's what Swiss German, French, and Italian is that it, and also Romesh? Yeah.