Pustejovsky (1995) rekindled debate on the dual problems of how to represent lexical meaning and on the information that is to be encoded in a lexicon. For natural language processing such as machine translation, these are important issues. When a lexical-conceptual mismatch occurs in translation of corresponding words from two different languages, the appropriate representation of their meanings is very important. This paper proposes a new formalism for representing lexical entries by first analysing observable mismatches in comparable pairs of nouns, verbs, and adjectives in English and Korean. Inherent mis-interpretations and mis-readings in each pair are identified. Then, concept theories such as those presented by Ganter and Wille (1996) and Priss (1998) are extended in order to reflect the cognitivist view that meaning resides in concept, and also to incorporate the propositions of the so-called ‘multiple inheritance’system. An alternative to the formalism of Pustejovsky (1995) and Pollard & Sag (1994) is then proposed. Finally, representative examples of lexical mismatches are analysed using the new model.