This research empowered communities in the poorest parts of the world to engage actively with Non-Governmental Organisations (NGOs) that provide lifesaving aid. It demonstrated that local languages are crucial for NGOs to build strong relationships with communities and ensure successful delivery of development projects. Yet, remarkably, NGOs and government donors have historically regarded translation and interpretation as a low priority. NGOs serving hundreds of thousands of people in Malawi and Peru adopted the recommendations, which has led to improved community engagement with NGO projects and more positive practical outcomes for such work. The research has been promoted as a vital contribution to UK government aid policy through Parliament and the UK’s national academies.