The Bilingual Lemma Activation Model as a Comparative Approach to Codeswitching

This paper explores intrasentential Codeswitching (CS) as a commonly observed bilingual speech behavior. Different from surface-based models, it investigates CS at an abstract level by relating the nature and activity of the bilingual mental lexicon in bilingual speech production to the structural principles governing CS. The Matrix Language Frame (MLF) Model is adopted for describing some fundamental structural principles governing CS, and the Bilingual Lemma Activation Model (BLA) is proposed for explaining the linguistic motivations for CS. Based on the analysis of some naturally occurring CS instances involving various language pairs, this study supports the claim that one of the bilingual’s languages is activated as the Matrix Language (ML) and the other as the Embedded Language (EL), and content and system morphemes are unequally activated. It is the ML which provides the sentential frame for CS and the EL only provides content morphemes switched into this frame. It further argues that bilingual mental lexicon contains not only lexemes but also more abstract elements called “lemmas”, and lemmas in the bilingual mental lexicon are language-specific and such lemmas are in contact in CS. This study provides evidence that only conceptually activated EL lemmas can be switched into the ML sentential frame.