A virtual private assistant (VPA) is configured to analyze various types of input that indicate one or more behaviors associated with a user and to determine the emotional state of the user based on the input. The VPA also determines one or more operations to perform on behalf of the user based on the input and the determined emotional state. The VPA then executes the one or more operations and synthesizes an output based on the emotional state of the user and the one or more operations. The synthesized output includes one or more semantic components and one or more emotional components derived from the emotional state of the user. The VPA observes the behavior of the user in response to the synthesized output and then implements various modifications, based on the observed behavior, to improve the effectiveness of future interactions with the user.