25. A system for providing a cooperative conversational voice user interface, comprising: a voice input device configured to receive an utterance during a current conversation with a user, wherein the utterance includes one or more words that have different meanings in different contexts; and a conversational speech engine, wherein the conversational speech engine includes one or more processors configured to: accumulate short-term shared knowledge about the current conversation, wherein the short-term shared knowledge includes knowledge about the utterance received during the current conversation; accumulate long-term shared knowledge about the user, wherein the long-term shared knowledge includes knowledge about one or more past conversations with the user; identify a context associated with the utterance from the short-term shared knowledge and the long-term shared knowledge; establish an intended meaning for the utterance within the identified context to disambiguate an intent that the user had in speaking the one or more words that have the different meanings in the different contexts; and generate a grammatically or syntactically adapted response to the utterance based on the intended meaning established within the identified context.
25. A system for providing a cooperative conversational voice user interface, comprising: a voice input device configured to receive an utterance during a current conversation with a user, wherein the utterance includes one or more words that have different meanings in different contexts; and a conversational speech engine, wherein the conversational speech engine includes one or more processors configured to: accumulate short-term shared knowledge about the current conversation, wherein the short-term shared knowledge includes knowledge about the utterance received during the current conversation; accumulate long-term shared knowledge about the user, wherein the long-term shared knowledge includes knowledge about one or more past conversations with the user; identify a context associated with the utterance from the short-term shared knowledge and the long-term shared knowledge; establish an intended meaning for the utterance within the identified context to disambiguate an intent that the user had in speaking the one or more words that have the different meanings in the different contexts; and generate a grammatically or syntactically adapted response to the utterance based on the intended meaning established within the identified context. 36. The system of claim 25 , wherein the grammatically or syntactically adapted response comprises a multi-modal output that includes one or more non-voice outputs that relate to the utterance or one or more tasks executed to process a request identified from the intended meaning.