ABSTRACT
Perennial questions about bilingualism concern the relationship between the two language systems in the same mind. Do they form two separate systems for processing language or a single combined system? Does one language aid or interfere with the other? Are there differences in areas of the mind, other than language, between a person who knows one language and someone who knows more than one? The more complex system involving two languages may confer benefits or losses on areas of the mind other than language: Bilinguals and monolinguals may think in different ways.
