Sharing is an important social behaviour for promoting reciprocal interaction and interactive play among peers, but previous studies have only trained giving and accepting behaviours. We trained appropriate asking in addition to giving, and tested for functional independence. Three socially isolated children were first trained either to ask appropriately for their turn with a toy, or else to offer the toy to a confederate child, and this was reversed after stability. There was an immediate increase in whichever behaviour was trained, but the other behaviour showed no increase until it was directly trained. This was replicated with two nondisabled children. Follow-up assessments on all five children showed some maintenance up to a month after training. These studies demonstrate that appropriate giving and asking are functionally independent, at least in this experimental setting; that this is not restricted to socially isolated children; and that asking does not emerge from training giving alone. It was argued that, while these results could be due to instructional control rather than the more natural consequences of sharing, such social rules or norms are typically taught as instructions from teachers and parents.