1. A system for representing natural languages in a common machine-readable form, called interlingua, comprising a lexicon and a grammar, where: a. said lexicon comprises: 1. a system of specifically designed classification codes for prototypical words of noun, adjective, verb, and adverb respectively, 2. virtual codes for each kind of derived words, 3. a system of synonymous feature set for synonymous word and metaphorical feature set for metaphorical sense of word, b. said grammar comprises: 1. a system of classification code and composition for prototypical clause, 2. a system of time feature set, space feature set, and adverb feature set, 3. a system of variational feature set for variational clause and synonymous feature set for synonymous clause, and 4. a system of metaphor processing procedure, and c. said prototypical verb word and said prototypical clause comprising said prototypical verb word share the same classification code, whereby a sense of a word of a language will be: a. matched to a unique interlingua classification code if it is prototypical, or b. if it is synonymous to a prototypical word then matched to the same classification code of said prototypical word plus a feature of synonymy, or c. if it is a derived word then matched to a virtual code plus the interlingua classification code of its stem word and a feature of derivation, or d. if it is a fixed extended sense then matched to an interlingua classification code of a word corresponding to said extended sense plus a feature of extension, or e. if it is a multiple use case then matched to an interlingua classification code of a word corresponding to said multiple use plus a feature of multiple use, or f. if it is used in a special clause or idiom then treated according to the corresponding rule governing said special clause or idiom respectively, and whereby a clause of a language will be: a. matched to a unique interlingua classification code of its comprised verb if both said clause and said verb are prototypical, or b. if said clause is variational and its comprised verb is prototypical then matched to the same interlingua classification code of its associated prototypical clause plus a feature of variation, or c. if said clause is prototypical and its comprised verb is not prototypical then matched to an interlingua classification code of a verb corresponding to said verb according to said verb being derived, fixed extended, or multiple use plus a corresponding feature of said verb, or d. if said clause is variational and its comprised verb is not prototypical then matched to an interlingua classification code of a verb corresponding to said verb according to said verb being derived, fixed extended, or multiple use plus a corresponding feature of said verb and a variational feature of said clause, or e. if said clause is a special clause then matched to an interlingua classification code for special clause plus a feature of special clause.