VietTESOL International Convention 2026

Vietnam's national plan (2025–2035) to reposition English from a foreign to a second language assumes a transition led mainly by formal schooling. Yet recent survey evidence suggests English has already entered everyday Vietnamese communication through informal, peer-mediated channels, especially among Generation Z. This study draws on a quantitative survey of 401 Vietnamese Gen Z students (born 1998–2009) across secondary and tertiary education in the Mekong Delta, examining their code-mixing practices and language attitudes through a 30-item questionnaire. Results show that English-Vietnamese code-mixing is widespread, with around 89% of respondents reporting some mixing in daily speech, though mostly at low intensity. A clear attitude-behavior gap emerges: among students who agreed with the media claim that mixing English reduces the purity of Vietnamese, nearly 89% still reported mixing in practice. One-way ANOVA shows that the most frequent mixers express the strongest agreement with the purity discourse, with the effect significant at the conventional level. Three mechanisms appear to drive this gap: linguistic automaticity, communicative accommodation to interlocutors, and in-group marking among Gen Z peers. The findings suggest Vietnam's EFL-to-ESL transition is already partially underway through bottom-up multilingual practice, and point to a pedagogy built around metalinguistic awareness rather than purity-based prescription.