This article discusses the importance of adult language learning when a minority language is threatened. Language acquisition planning attempts to reproduce the language across generations. The research context is Wales with its strong history of adults learning Welsh. The history of the Welsh language shows a decline in the last century, but increased emphasis on language acquisition planning, including adults learning Welsh, has halted the decline. Using a longitudinal design and a multi-method approach, the research aims to understand learners' expectations, experiences, outcomes and course issues such as retention and progression. The article reports the initial results from a sample of 1061 adults beginning to learn Welsh, obtained using questionnaire survey methodology. The results suggest that there is a match between the motivations and aspirations of adult language learners and the theory of language acquisition planning. Integrative motivation was stronger than instrumental motivation in commencing the Welsh language-learning course, although both motivations were present and can be regarded as conceptually but not necessarily psychologically separate. Managing the expectations of course members to enable higher retention rates was found to be important. Language acquisition planning depends on such learners moving to fluency in the language, and thereby to daily language use. (Contains 3 figures and 3 tables.)