20. An electronic device, comprising: one or more processors; and memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for: receiving user speech input; generating a textual representation of the user speech input; parsing the textual representation to determine a primary domain representing a user intent for the textual representation; identifying a first substring from the textual representation that corresponds to a first attribute of the primary domain; parsing the identified first substring to determine a secondary domain representing a user intent for the first sub string; performing a task flow comprising one or more tasks based on the primary domain and the secondary domain; and outputting a response in accordance with the performed task flow.
20. An electronic device, comprising: one or more processors; and memory storing one or more programs configured to be executed by the one or more processors, the one or more programs including instructions for: receiving user speech input; generating a textual representation of the user speech input; parsing the textual representation to determine a primary domain representing a user intent for the textual representation; identifying a first substring from the textual representation that corresponds to a first attribute of the primary domain; parsing the identified first substring to determine a secondary domain representing a user intent for the first sub string; performing a task flow comprising one or more tasks based on the primary domain and the secondary domain; and outputting a response in accordance with the performed task flow. 21. The electronic device of claim 20 , wherein parsing the textual representation comprises: determining a confidence score for a plurality of interpretations of the textual representation; and determining the primary domain representing the user intent for the textual representation based on an interpretation of the plurality of interpretations of the textual representation having the highest confidence score.