Bilingual education

Bilingual education is an approach in which two languages are used as media for teaching curriculum subjects. It is distinct from a course that teaches another language only as a subject: learners also study subjects such as mathematics or science through the languages used in the programme. Depending on the setting, goals may include access to subject learning while pupils develop proficiency in a new language, sustained literacy in a home or community language, or bilingualism and biliteracy. The label covers varied practices, and its legal and educational meaning differs among countries. UNESCO’s 2025 global guidance places multilingual education within broader efforts to make learning more inclusive and to enable children to learn in languages they understand.

Programmes differ in their aims and in how much instruction is delivered in each language. Some transitional approaches use a learner’s home language to support subject learning while the learner develops the dominant or national language; maintenance-oriented approaches aim to continue developing both languages. In dual-language programmes, subject teaching takes place in a partner language as well as English or another main language. A one-way programme serves students largely from one language background, while a two-way programme brings together students from two language backgrounds and teaches through both languages. These labels are used especially in U.S. education policy; equivalent programmes elsewhere may have different names or structures.

A central policy question is how to help learners gain proficiency in a widely used instructional language without unnecessarily restricting their access to academic content or abandoning development of a home language. A 2017 consensus report by the U.S. National Academies described English-dominant instruction and bilingual instruction as distinct approaches; its review of evaluation studies found English outcomes in bilingual programmes were generally comparable to, or sometimes better than, those in English-only programmes, with longer-term studies in its evidence base finding benefits. UNESCO’s guidance likewise advocates language-in-education policies that recognize linguistic diversity and support learning in languages pupils understand. These conclusions concern particular evidence bases and policy settings, not a guarantee that every programme will produce the same result.

Research findings depend on which students, languages, subjects, and programme designs are studied. In its 2022 review of U.S. dual-language programmes, the What Works Clearinghouse found that only two of 45 reviewed studies met its evidence standards. It rated the evidence as potentially positive for English literacy achievement, based on one qualifying study, and uncertain for mathematics and science. The review cautioned that effects across most settings remained unknown and called for more rigorous research across student populations, partner languages, and programme models. Implementation also requires more than choosing two languages: schools may need teachers able to teach in the partner language, aligned curricula and assessments, suitable materials, and sustained support. UNESCO identifies limited teacher capacity and shortages of learning materials in some languages as continuing challenges.