1. A method comprising: receiving, during a natural language dialog between a user and a computing device, an utterance; generating, via a processor, a semantic and syntactic graph using the utterance; extracting possible combinations of features from the semantic and syntactic graph, to yield extracted n-grams; comparing the extracted n-grams to previously classified n-grams, to yield a comparison; classifying the utterance as being associated with a call type based on the extracted n-grams and the comparison, to yield a classified utterance; and responding to the user in the natural language dialog based on the classified utterance.