It's interesting to see the language boundaries they've set for themselves. The other day, we were walking home from the bus stop with neighbors and I asked my 6 year old (in German) how his day had been. He quickly responded, "Nein, nicht Deutsch". (No, not German). Clearly, he had decided that one of his language boundaries was that among school friends, he would only speak English. Our home and family has always been regarded as a purely German speaking area for the younger children. But within this German-speaking boundary, they have established a few English areas. They have established imaginative play as a time when they often (not always) speak English at home. I don't interfere, because they need a time to practice English. And so far, the English is well contained within the boundary of the game.
The following video is an excellent example of how they "play" in English but "communicate" in German. They are all playing a Dr. Suess A,B,C game with my help. This game can't very well be played in German because the letters stand for different objects (F for fork), which don't work in German. So, they have dubbed it an Englishes Spiel and play it in English.
You can hear (at least I can hear) that they have more of a "foreign" accent in English than they do in German. They are playing the game in English, but discuss the rules and questions they have in German. Simon starts out by saying "Jetzt ist dein dran" using the English syntax "Now it's your turn" instead of "Jetzt bist du dran." Often they have to ask me what a word is in English. Jonathan asks me what the letter Q is in English. He also calls the ice cream cone Eis (which is the German word for icecream). Simon struggles with the word put, he keeps saying "Tut you foot in a elephant", instead of "Put your foot on the elephant". Of course, he's thinking about the German word tun. I also think it's interesting that when Jonathan doesn't know the word for kite, he refers to it as dragon. The German word for kite is Drachen. The German word for dragon is Drache (which is very similar). It's interesting to see him make that connection.