As a response to an ageing population, and to benefit from senior citizens’ resources and improve their quality of life, European countries are increasingly engaging older volunteers in the old-age sector and care environments. Older Danes’ participation in volunteer work is high; however, nursing home residents and home care recipients are typically not part of these initiatives as volunteers, but as the receivers of volunteer care. We investigate an initiative that engages frail older people as volunteer language teachers for foreigners learning Danish in an endeavour to utilise their resources as volunteers and to engage the language teachers socially. Through participant observations and semi-structured interviews with older volunteers, Danish-language students and care personnel, we explore what constitutes good social relationships in this specific initiative, how these relationships are created and the kind of subject that appears through Elderlearn. We are inspired by the sociology of attachment as we describe how frail older people emerge as engaged subjects by becoming reattached to their life histories, interests, abilities and relational skills. In this regard, good social relationships surpass the immediate volunteer–recipient bond and create a ‘blurry volunteering’ with less distinct divisions of who gives and who receives. This generates constructive relationships created through interlinguistic competences, international consciousness, and use of materials, objects and the local community. We argue that this arrangement reattaches the language teachers to their life histories, thereby enabling the emergence of a different kind of international and engaged old-age subjectivity.