A Corpus-Based Evaluation of Lexical Coverage in A2-Level EFL Coursebooks

Abstract

This article reports a corpus-based study of A2-level English as a Foreign Language (EFL) coursebooks, focusing on their lexical coverage, frequency-based vocabulary distribution, and cross-linguistic lexical overlap. Textbook corpora compiled from student books were analysed using the New General Service List (NGSL), the NGSL supplementary word list, and the New Academic Word List (NAWL) to establish vocabulary load and coverage in relation to the 95% and 98% comprehension thresholds. The results show that the coursebooks rely heavily on high-frequency vocabulary. Combined coverage from the NGSL bands, supplementary list, and NAWL ranges from 94.47% to 95.89%, indicating that the materials support comprehension with some instructional assistance, while remaining below the level associated with largely independent reading. NGSL-only coverage remains high (92.15%–93.93%), whereas academic vocabulary contributes minimally. Analysis of Turkish–English cross-linguistic overlap reveals that cognates constitute a small proportion of the lexical input, while false cognates occur at consistently higher rates across materials. These results suggest minimal variation in lexical demands across publishers and provide empirical evidence to inform textbook selection, materials development, and vocabulary pedagogy for A2-level learners.