Abstract

Informal second language learning, a growing area of interest in second language acquisition research, refers to self-directed and often unintentional exposure to a second language outside structured educational settings. In the context of English as a foreign language, particularly in countries like Vietnam where English is not widely spoken in daily life, informal learning can play a crucial role in supplementing formal instruction. Learners engage with English through various means, such as digital media, social platforms, and entertainment, which provide authentic language input and can significantly boost motivation and language proficiency. Although this phenomenon has gained attention worldwide, research on informal second language learning in Vietnam remains scarce, especially regarding how learners engage in such contexts. To fill this gap, this study explores the extent to which Vietnamese English as a foreign language learners engage in informal second language learning activities. To this end, the data were collected from 96 undergraduates at one university in Ho Chi Minh City using a questionnaire adapted from existing theoretical frameworks. The questionnaire measured engagement across different activities in four dimensions: behavioural, cognitive, affective, and linguistic engagement. To uncover engagement patterns, the data were analysed using the descriptive statistics, analysis of variance (ANOVA), linear mixed models, and cluster analysis. The findings indicate that participants engage in certain informal activities that trigger strong affective and cognitive engagement, while others, requiring greater linguistic engagement, generate less emotional engagement. The cluster analysis revealed two distinct clusters of activities: one comprising receptive and interactive activities (e.g., video watching, conversations) that elicit high affective and cognitive engagement, and another including text-focused tasks (reading, writing) that involve greater linguistic engagement but much lower affective engagement. These results emphasise the role of multimedia and social interaction in enriching informal language learning experiences while also highlighting the difficulty of maintaining interest in more linguistically demanding activities. The study’s insights offer valuable practical implications for English learning and teaching in Vietnam, as well as suggestions relevant to the country’s national goals of promoting English as a second language in education.