The current paper proposes a frame-based account to conceptual shifts in the countability do-main. We interpret shifts in noun countability as syntactically driven metonymy. Inserting a noun in an incongruent noun phrase, that is combining it with a determiner of the other countability class, gives rise to a re-interpretation of the noun referent. We assume lexical entries to be three-fold frame com-plexes connecting conceptual knowledge representations with language-specific form representations via a lemma level. Empirical data from a lexical decision experiment are presented, that support the as-sumption of such a lemma level connecting perceptual input of linguistic signs to conceptual knowledge.