I was once standing in the tower on top of Castle Montebello in Bellinzona, looking out at Castlegrande. There was a group of schoolchildren up there with me. As I listened to them speak, I heard some speaking German and some speaking Italian. After a bit I realized they were coming from the same kids, and I surmised it might be Romansh. Always sad to think of unique cultures disappearing into the ether of history.
That's what some bilingual kids do when they talk to each other. They switch between languages flawlessly and mid-sentence. Drives me nuts when I'm listening to them. Similar effect you get when you live abroad for a while, there's certain idioms you can easily express in another language/culture but you won't find the words in your native language.
