Speech data is processed with one or more dynamic grammars, to reduce latency and improve accuracy. Different speech grammars are used by a speech recognition process depending on a context experienced by a speaker, and sentence grammars are similarly varied during a natural language process. The methods are useful for distributed speech recognition systems such as a client-server system, typically implemented on an intranet or over the Internet based on user queries at his/her computer, a PDA, or a workstation using a speech input interface.