["Developmental Science, Volume 29, Issue 5, September 2026. ", "\nABSTRACT\n\nThis article examines preschool attendance and reading proficiency among students from families that do not speak the test language at home. Both indicators are key targets of the United Nations' Sustainable Development Goal 4, which aims to promote equity in education. We analyze gaps in reading achievement and preschool participation between students who speak the test language at home and those who do not. The study also considers how these gaps intersect with socioeconomic background, focusing on students who face both linguistic and economic barriers. Using data from the 15 education systems that participated in all progress in international reading literacy study (PIRLS) cycles, we assess how these gaps have developed over time. Our findings show that significant gaps persist in most educational systems and, in some cases, have even widened. These social inequalities are especially marked among students with low socioeconomic status. We further examine how preschool attendance relates to reading achievement in grade 4 and whether this relationship varies by language and socioeconomic background. The analysis reveals that preschool attendance is particularly beneficial for students from non‐test‐language and lower socioeconomic backgrounds‐groups that are also less likely to have access to early education. Our findings highlight a paradox: the children who would benefit most from attending preschool are those least likely to have access to it.\n\n\nSummary\n\nAccess to preschool for non‐test‐language students has stagnated, with a growing gap in access between families speaking the test language at home and those who do not.\nA persistent basic literacy gap exists between family language groups, especially among students from lower socioeconomic backgrounds.\nPreschool attendance improves basic literacy outcomes, especially for doubly disadvantaged students from non‐test‐language backgrounds and lower socioeconomic status.\nThis presents a notable paradox: those who benefit the most from attending pre‐primary education are also the ones that are least likely to attend.\n\n\n"]