Bilingual Complex Abstract Lexical Structure and Its Relevance to Interlanguage Studies

Abstract

This study adopts two assumptions about abstract lexical structure. One is that lexical structure is modular: lexical information is organized into subsystems pointing to different levels of linguistic structure, and parts of lexical structure can be split and recombined. The other concerns the sources of morphemes actually occurring in surface strings. As commonly recognized, abstract lexical structure contains three levels: lexical-conceptual structure, predicate-argument structure, and morphological realization patterns. This study argues that abstract lexical structure becomes “complex” because the bilingual mental lexicon contains lemmas (i.e., abstract entries about lexemes) from different sources, such as learners’ first language, their target language, and their interlanguage. By adopting a multi-layered speech production model (Levelt, 1989; Myers-Scotton & Jake, 2001; Wei, 2002, 2015, 2020), it further argues that different types of morphemes are accessed at different levels of language production, resulting in different degrees of learning difficulty (an implicational hierarchy of second language morpheme acquisition) and different types of learner errors in interlanguage production. The typical instances of learner errors for the study are collected from interlanguage performance by adult second language learners with various first language backgrounds. This study aims to explore the nature of the bilingual mental lexicon and mechanisms of interlanguage development.