10. A method for processing discourse input comprising: at an electronic device with a processor and memory storing one or more programs for execution by the processor: receiving a discourse input from a user; determining a text string corresponding to the discourse input, wherein determining the text string comprises: determining, using a first language model, a conditional probability of a candidate word in the discourse input given one or more words in the discourse input; and applying a weight to the conditional probability of the candidate word given the one or more words to obtain a weighted conditional probability of the candidate word given the one or more words, wherein the weight is based on a conditional probability of the candidate word given one or more classes associated with the one or more words, and wherein the text string is based on the weighted conditional probability of the candidate word; and generating an output based on the text string.
10. A method for processing discourse input comprising: at an electronic device with a processor and memory storing one or more programs for execution by the processor: receiving a discourse input from a user; determining a text string corresponding to the discourse input, wherein determining the text string comprises: determining, using a first language model, a conditional probability of a candidate word in the discourse input given one or more words in the discourse input; and applying a weight to the conditional probability of the candidate word given the one or more words to obtain a weighted conditional probability of the candidate word given the one or more words, wherein the weight is based on a conditional probability of the candidate word given one or more classes associated with the one or more words, and wherein the text string is based on the weighted conditional probability of the candidate word; and generating an output based on the text string. 17. The method of claim 10 , further comprising: determining, using a third language model, the conditional probability of the candidate word given the one or more classes.