Abstract: An adaptive virtual assistant system can be configured to change an attribute of a virtual assistant based on user responses, environmental conditions, and/or topics of discussion. For example, the virtual assistant system can determine, based at least in part on user data, a communication profile that is associated with the virtual assistant and determine first communication data comprising a first communication attribute based on the communication profile. In some instances, the system can transmit the first communication data to a user device and receive, from the user device, input audio data representing a user utterance. Based at least in part on the input audio data, the system can determine second communication data comprising a second communication attribute and transmit the second communication data to the user device.