Vocabulary structure in foreign language learners: a complex network analysis perspective

Abstract This empirical study explores the vocabulary structure of heritage minority learners of English as a foreign language (EFL) within a Spanish mainstream educational context. Using graph analysis and complex network theory, the study examines lexical organization among learners of local origin (Spanish monolinguals) and heritage multilingual learners from Arabic, Romanian, and Urdu backgrounds. Results reveal no significant quantitative differences in lexical production among groups, but qualitative distinctions in lexical-semantic structures emerge. Heritage learners exhibit vocabulary networks influenced by their linguistic and cultural backgrounds, with distinct cluster formations compared to local learners. Small-world properties characterize all lexical networks, indicating efficient word retrieval structures. Findings highlight the role of schooling in standardizing vocabulary acquisition while cultural and linguistic experiences shape lexical access patterns. The study underscores the need for plurilingual approaches in EFL education to accommodate diverse linguistic backgrounds.