A method and system for processing, storing, retrieving and presenting information with an extendable interface for natural and artificial languages. The system includes an interpreter, a knowledge base, and an input/output module. Making use of an internal representation based on sorted-type theory, the system stores information in the knowledge base, answers queries from clients, and processes erroneous or contradictory information according to a dynamically adjustable set of rules. The system also stores language definitions in the knowledge base, enabling the system to communicate with clients in a variety of natural and artificial languages. New languages may be added to the system by presenting definitions expressed in a language already incorporated within the system.