Supporting Oral Language Development Children with a small vocabulary are at a disadvantage for all aspects of learning. Unless there is targeted support, children who start slow will continue to fall behind their language-rich peers.  A powerful way to ensure all children are ready for learning, particularly in school, is to offer high quality oral language education early in a child's life.  The power of early language intervention is supported by a large body of evidence showing a combined foundation of strong spoken language and listening comprehension cascading to reading and writing skills.  However, little is known about the efficacy of oral language interventions in low- and middle-income countries where communities are often multilingual.  We aim to address this gap in the literature through a mixed-methods study with children ages of 3-to-6 living in India and the Philippines.  The study will examine oral language development under the particular complexities of multilingual urban poor settings.  Research in these settings is of importance as there is reason to believe resources that spontaneously support children's language development may be under strain for the urban poor (e.g. reduced social networks, a new school language), making them a particularly vulnerable group for school failure.  A co-developed project  The proposed project was co-developed by multiple agencies.  Government partners shared that a pressing systemic concern was the low literacy rates in primary schools.  Community partners stressed the need for evidence on quality programs that will work in local schools and university partners echoed the need for a comprehensive program of research.  We therefore propose to understand children's language development in-context and will test an intervention that could potentially better prepare children for primary school.  The research sites will be Udupi district in India and Quezon City in the Philippines.  Defining characteristics of these sites include the multiple languages around the child and a policy commitment to either mother-tongue or multilingual education.  Hence, these contexts offer an opportunity to research a topic that is understudied in not just DAC countries but also internationally: children's oral language development and oral language intervention in a multilingual setting.  Objectives and Outputs  The primary objective of this research is to provide descriptive and causal evidence on quality (in early childhood development and pre-primary education) and readiness (for primary education) through three studies that aim to a) map opportunities and barriers to oral language development, b) validate assessments to track children's developing oral language and c) examine a targeted intervention delivered by teachers one year before entry into primary school.  We will map opportunities and barriers by following thirty children over one day to record their language experiences, examining language knowledge of their conversation partners, and conducting an ethnographic inquiry of classes they attend.  We will finetune fifteen assessments by analyzing 3000 data points on each test and, in a study with 800 children, evaluate a language intervention designed with teachers that draws upon folk tales and local narratives.  This inter-disciplinary project will provide an approach to reach the Sustainable Development Goal of effective learning outcomes for all children by focusing on the language bedrock of early childhood learning.  Outputs include evidence briefs for policy makers and open access toolkits for educators. Multiple bodies of data for the research community will expand the evidence-base in these contexts.  These include a word bank, an archive of child language, a rich description of talk in the classroom, performance data and outcomes data.  Taken together, the proposed research could potentially act as a catalyst for informed early childhood education in India, the Philippines, and other DAC countries. The Global Challenges Research Fund (GCRF) supports cutting-edge research to address challenges faced by developing countries. The fund addresses the UN sustainable development goals. It aims to maximise the impact of research and innovation to improve lives and opportunity in the developing world.