Observing unmarked use of borrowing and a change in code from the mother's preferred language to the child's when on his own, the author concludes that bilinguals have a preferred, unmarked language that is used outside of social constraints, i.e. when they are left alone. As such, a case is made for non-pragmatic constraints in codeswitching, a distinction between codeswitching and borrowing is drawn and the role of codeswitching as a marker of interpersonal relationships is confirmed.