Language can be so neat. This Sunday I went for a playdate with a Hong Kong friend of mine. She speaks Cantonese, Mandarin and Danish. I speak Mandarin, Danish, English, Japanese and French. My son speaks English and Danish. Her daughter speaks Cantonese and Danish. My friend and I usually default to Mandarin, since we're both the most comfortable with it as the common tongue of China. The kids, however, since they're growing up in Denmark and go to børnehave both are used to Danish as their common tongue. As a result, us adults ended up defaulting to Danish, because then both kids could understand and even felt more comfortable with the situation. Børnehave (literally children's garden, but I feel calling it kindergarten is a false equivalency) is required for all three year olds who fail their Danish language test, though I think a lot of immigrants voluntarily sign their kids up before ever being tested, certainly we did. It has the interesting effect of not only assimilating the kids, but forcing their parents to assimilate as well, since Danish becomes the common tongue no matter where they are from. It's really neat.