To stimulate children to initiate and to continue engaging in an activity, parents can rely on different motivating styles. According to Self-Determination Theory, parents can be autonomy-supportive and inviting, thus encouraging children’s sense of choice and ownership. They can also be controlling and domineering, thus pressuring the child to think, act, or feel in parent-prescribed ways. Abundant research focused on what parents do and say, that is, the motivational content, when parents direct their children (“what”-component). Yet, no parenting study to date has examined the way in which these motivational contents are expressed non-verbally, that is, through a different tone of voice (i.e., prosody; “how”-component). It is well possible that unique voice characteristics, such as sharpness, speed, and volume, influence children’s reactions. In three experimental studies among parents of toddlers, this proposal will examine (1) whether autonomy-supportive and controlling motivational contents are conveyed through differential voice patterns; (2) the unique and interactive contribution of the motivational content and the motivational prosody in the prediction of children’s motivational, behavioral, and physiological reaction patterns during a cleaning and puzzle solving task; (3) if autonomy-supportive and controlling motivational prosody can be experimentally activated when parents are placed under pressure, as they often are in daily life.