This article draws on two studies of language diversity and adult literacy education in Timor-Leste that were conducted in different regions of the country between 2009 and 2013. Its central focus is on the day-to-day language practices and language values of local participants and the way in which these practices and values relate to national language policies. We first outline the views of language and of language policy-making that underpin our article. We then provide a brief overview of language-in-education policy-making in Timor-Leste with respect to provision for adult literacy. After that, we describe the design and conduct of the two studies and we present selected findings, drawing on both quantitative and qualitative data sources. The quantitative data were generated by means of questionnaire-based interviews and the research participants' own accounts of their language repertoires, practices and values. The qualitative data were gathered via: (1) observation of adult literacy classes; (2) analysis of photographs of signage in local linguistic landscapes. We conclude with a discussion of the implications of our findings for language-in-education policy development in the area of adult literacy provision in countries in the global south, such as Timor-Leste. Here we plead for a greater involvement of teachers and learners as actors, not mere bystanders, who can bring new voices into policy-making processes and into research into these processes.