1. A method for recognizing speech, the method comprising: at an electronic device: receiving user-specific usage data comprising one or more entities and an indication of user interaction with the one or more entities; and receiving speech input from a user; in response to receiving the speech input: composing a weighted finite state transducer having a first grammar transducer with a second grammar transducer, wherein the second grammar transducer comprises the user-specific usage data; transducing the speech input into a word and an associated probability using the weighted finite state transducer composed with the second grammar transducer; and outputting the word based on the associated probability.
12. The method of claim 1 , wherein outputting the word comprises: transmitting the word to a virtual assistant knowledge system.