One of the most common problems with raising bilingual children is that the child might refuse to use one of the languages. This happens for two reasons. First, the child might not have had enough opportunities to practice this language and so he is not strong enough to function in that language. And the other reason is that the parent might not have enforced the use of the other language. So maybe the parent himself mixed languages or maybe he allowed the child to respond in English. So usually this problem should not arise if, from the beginning of language socialization, the child is taught to use the appropriate language. What does that mean? When the child starts speaking at age 12-14 months and comes to mommy and says, "Ooh, this is a ball," mom could say immediately something like, "Well, daddy says ball but mama says bala." So you're already teaching the child as to the language that you're expecting. This is the same way as we teach children to be polite. We ask for the magic word. And so we could also ask for the language that we're expecting. If you socialize the child into this pattern from the beginning, he or she should not get into the trouble not wanting to speak the language. Again, the refusal to speak a language is due to the fact that the child might not have practiced enough that language. If we get to the point that we have to basically create opportunities for the practicing of that language, it might mean taking a trip to the country of origin where the child can hear more of that language, it might mean increasing the opportunities to hear that language, it might mean a reward system where you really praise the child and reward him for using the other language. But it's hard to undo what has been done in the early years. And so it's very important that parents from the very beginning not only use the language they want the child to learn, but that they encourage the child to respond in the language that is expected.