The MultiLila project aimed to investigate the role of language of education and multilingualism in the individual and the society on language, school and cognitive skills in underprivileged primary school children. We focused on schools in three sites in India (Patna, Hyderabad and Delhi), and directly assessed 2,500 children in government schools, on language abilities, literacy, critical thinking and problem-solving skills, mathematical reasoning and non-verbal cognition. A child questionnaire including demographic information, language history and current language practices questions as well as questions on socioeconomic background and contextual linguistic diversity was completed for each participant. Furthermore, we surveyed the children’s teachers and head-teachers on their respective language attitudes, teaching methods and qualifications in order to evaluate the linguistic and pedagogical resources available to the child participants. Detailed classroom observations were also collected which included a detailed record of number of languages used by teachers and learners during classroom activities within a 30-minute period of observation. Detailed information on the project findings can be found in https://www.mam.mmll.cam.ac.uk/ and the final research report in https://www.mam.mmll.cam.ac.uk/Publications/Projectfinalreport . The project has led to two follow-up projects which are currently underway in Hyderabad focusing on a classroom intervention targeting reading comprehension strategies through multilingual resources.