> Also, be more stubborn than them if they try to only speak German. I think that's the main thing. I have been very stubborn in "not understanding" the other

> Also, be more stubborn than them if they try to only speak German. I think that's the main thing. I have been very stubborn in "not understanding" the other (local) language with my children, even if it's obvious to them I do understand it. Today (they are still young) they speak both languages, including between themselves, and they don't seem to have a preference for one language over the other.