I move around in these kind of families , my wife is not very conversant in English so the kids talk to her in toti photi Urdu, they talk to each other in English. I talk to them in English. Kids of a friend cannot speak Urdu at all they are Muslims from Kerala , but these kids also understand whatever we say to them in Urdu. I think Urdu is Jannat key zuban and the kids learn it there before coming to this world.:)