The World Bank's focus on foundational skills requires that issues of language and Language of Instruction be brought to the forefront of education policy discussions. Poor Language of Instruction policies harm learning, access, equity, cost-effectiveness, and inclusion. Yet nearly 37% of students in low- and middle-income countries are taught in a language they do not understand. Massive learning improvements are feasible by teaching in a small number of additional languages. The World Bank's first Policy Approach Paper on Language of Instruction offers an indication of the work that will be undertaken to support countries in introducing reforms that will result in more resilient, equitable, and effective systems by promoting teaching in the languages that students and teachers speak and understand best. [The report was edited by John Steinhardt.]