I am also raising a bilingual 3–year-old in Spain. I speak to him only in English. But i have recently read The Nurture Assumption by Judith Rich Harris, which

I am also raising a bilingual 3–year-old in Spain. I speak to him only in English. But i have recently read The Nurture Assumption by Judith Rich Harris, which argues convincingly that his English will be limited in certain important ways unless he also has a native English-speaking peer group.