1. A method comprising: for each of a plurality of speech applications, parsing a corpus of terms to produce a first output set, in which expressions identified in the corpus are replaced with corresponding grammar tags from a grammar that is specific to the application; for each of the plurality of speech applications, replacing each of the grammar tags in the first output set with a class identifier of an application-generic class, to produce a second output set; and processing collectively the second output sets or data derived from the output sets with a statistical language model (SLM) trainer to generate an application-generic class-based SLM.