VIETTESOL INTERNATIONAL CONVENTION 2025

Vocabulary knowledge plays a crucial role in the development of language skills and overall English proficiency among EFL learners. In Vietnam, the General Education English Curriculum (GEEC), introduced by the Ministry of Education and Training (MoET) in 2018, expects students to acquire about 2,500 words across primary to upper secondary levels (Van Van, 2022). However, the GEEC does not specify which words learners should know at each stage.
This study aims to develop the Vietnamese Learners’ Essential Lexicon (VLEX) - a list of 3,000 key lexical items for students up to the Upper-secondary level. This list is compiled by synthesizing data from two types of sources: (1) seven frequency-based wordlists, which are developed from large corpora using frequency counts and represent the words that learners should know, and (2) three knowledge-based wordlists, which are based on learner corpora or large-scale vocabulary testing and reflect the words that learners actually know at various proficiency levels. The integration of frequency-based and knowledge-based approaches enables a more balanced and realistic picture of learners’ lexical needs.
To validate the VLEX, its coverage was tested across four corpora reflecting widely used materials in Vietnam: (1) MoET-approved textbooks, (2) international ESL textbooks for young learners, (3) Cambridge English exam preparation resources, and (4) official national exams. Results show that the VLEX consistently outperforms its ten source lists in lexical coverage across all corpora. These findings suggest that the VLEX is a more effective and context-appropriate vocabulary resource for curriculum planning, teaching, and assessment in Vietnamese EFL education.
Key words: corpus linguistics, corpora, wordlist, vocabulary