ERROR PATTERNS IN THE INTERLANGUAGE OF VIETNAMESE EFL LEARNERS: A DUAL-TAXONOMY ANALYSIS OF ESSAY WRITING

Abstract

Errors constitute an inevitable yet informative feature of second language acquisition, offering direct evidence of a learner's developing interlanguage. Whereas error analysis in Vietnam has predominantly examined undergraduates in degree programmes, learners at intensive foreign language centres remain under-researched, and studies providing an integrated taxonomy of their errors are scarce. The present study, therefore, investigated the categories and prevalence of linguistic errors in argumentative essays by EFL learners in IELTS preparation courses at a foreign language centre in Ho Chi Minh City. Adopting a descriptive mixed-methods design, the study analysed 63 end-of-course essays, in which errors were manually classified using a Linguistic Category Taxonomy synthesised from Politzer and Ramirez (1973), James (1998) and Langan (2001), and re-examined through the Surface Strategy Taxonomy (Dulay, Burt, & Krashen, 1982). Of the 1,685 errors, lexical errors were the most frequent (29.3%), followed by morphology (27.4%), syntax (21.5%), sentence structure and discourse (11.7%) and mechanics (10.1%); misformation (52.58%) dominated the surface strategy dimension. The findings indicate that word choice, number, subject-verb agreement and spelling remain the most persistent difficulties, arguably attributable to L1 negative transfer coupled with intralingual overgeneralisation. It is contended that intensive, exam-oriented instruction does not by itself remedy fundamental linguistic deficits; pedagogical implications for form-focused writing instruction are discussed.