Language development in Arabic-speaking children in the early years: tackling the roots of academic and social inequalities The developmental period from 0-4 years lays the foundations of an individual's life-course, setting the trajectory for their long-term outcomes in health, education, employment and wellbeing. Language is at the heart of this trajectory. Because "skill begets skill" (Heckman, 2008), addressing language difficulties at this stage brings much greater gains and economic returns than when children are older. In the Arab world policy-makers tend to focus on later remedial programmes, with much reduced chances of 'narrowing the gap', especially for socially disadvantaged children. Across any population ~7% of children do not reach expected levels in language development. This corresponds to ~23 million children and adolescents with language difficulties in Middle Eastern and North African countries. Whilst these difficulties are found across the social spectrum, their prevalence is higher in socially disadvantaged families, reaching up to 40% in some UK schools.  This 4-year project is a multi-disciplinary collaboration between two UK universities (Newcastle and Plymouth) and the University St Joseph (Beirut), the Jordan University of Science and Technology, and Birzeit University (West Bank), with activities covering Egypt, Jordan, the West Bank and Lebanon. It brings together a team of linguists, psychologists, speech and language therapists, paediatricians and educators to develop the necessary knowledge and tools for effective Early Years policy in Levantine countries and Egypt. Our aim is to address the lack of culturally sensitive and standardised tools to measure language development in Arabic-speaking children, as a primary indicator of healthy development and the foundation skill for education. For this, we need to show the feasibility of a multi-dialect approach, and we need to quantify the effects of social disadvantage, multilingualism and childcare mode on language development. We also need to estimate how war-related traumas impact trajectories of language development in the region. Finally, we need to raise awareness of the importance of early language skills in the public and policy makers, empower end users with tools to screen children for language delays and provision for language-centered curricula, and disseminate the expertise of local practitioners for prevention and interventions. In WP1, we adapt and standardise the Communicative Development Inventory (CDI) across all four countries. The CDI is the Gold Standard parental questionnaire to assess vocabulary and language development in infants aged 8 months to 4 years. In WP2, we focus on Lebanon, where the multiethnic and multilingual situation creates an acutely complex picture. Using the CDI as an investigation tool, we define an accurate measure of social disadvantage and examine how the diversity of childcare mode impacts language skills. We evaluate the most efficient way to account for multilingualism by comparing the Arabic CDI to the Lebanese trilingual CDI. Finally, with the CDI, the ASQ (5 developmental domains) and the SDQ (socioemotional skills), we paint a full picture of developmental trajectories in Syrian and Palestinian refugee children in settlements and camps, to circle back contextualised information to NGOs and policy makers. In WP3, we set up a key stakeholder group and co-design appropriate methods to maximise the impact of knowledge gathered from WP1 and 2. In particular we develop an app version of the standardised CDI, providing free assessment and culture-specific, parent-centred activities. We co-create a series of social media campaigns, professional training events, seminars for practitioners and policy makers. With refugee families, we promote and evaluate Early Years activities geared towards getting children ready for school and reducing dropout rates. Beyond the focus on Lebanon, we assess the exportability of these initiatives to partner countries, with the long-term goal of reaching out to the rest of the Middle East. 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.