While skilled migrants make influential contributions to development through remitting cash and exchanging knowledge, we argue for greater scrutiny of the role of language in the so-called "migration-development nexus". Noting the transnational context within which the everyday life of many migrants proceeds, we develop a broader reading of language use which is attentive to its potential role in transforming social, cultural and spatial relations. Adopting a relational ontology to everyday practice, we describe how professional Zimbabweans used and experienced English, Shona and Ndebele in making various development contributions. While 82% of our respondents remitted, and most felt English was essential for employment success, our results also highlight how the placed nature of language use intensifies social and cultural vulnerabilities. We further explore how an emerging language practice addresses vulnerability through valuing a cross-cultural communicative competency which reworks spatial relations. That language use and practice are entwined with the economic, social, cultural and spatial reproduction of the migration-development nexus that has implications for critical accounts of globalisation and for policy on development and social cohesion.