1. A method of adapting an n-gram language model for a new domain, the method comprising: receiving background data indicative of general text phrases not directed to the new domain; receiving a set of semantic entities used in the new domain and organized in classes; generating background n-gram class count data based on the background data and the semantic entities and classes thereof; receiving adaptation data indicative of text phrases used in the new domain; generating adaptation n-gram class count data based on the adaptation data and the semantic entities and classes thereof; training a language model based on the background n-gram class count data and the adaptation n-gram class count data; and embodying the language model in tangible form.