Lead
"If we use two languages at home, won't the child end up half-competent in both?" This question confronts nearly every parent who is raising a child bilingually — whether by deliberate choice or because an international marriage simply made it the situation. The concern is not baseless. But the research suggests that what looks like a limitation, when examined carefully, is something else.
This article reviews the key studies on bilingual child development — vocabulary acquisition, executive function, and family language strategy — and attempts an honest account of what the evidence shows and what it does not.