According to the 1978 constitution, Spanish is the national language. Castilian, the dialect of the central and southern regions, is spoken by most Spaniards (74%) and is used in the schools and courts. Regional languages—Catalan (spoken by 17% of the population), Galician (7%), Basque (2%), Bable, and Valencian—are also official in the respective autonomous communities, where education is bilingual.
According to census data, regional languages were spoken by 16,307,921 persons in Spain. A majority of those who live in the northeastern provinces and the Balearic Islands spoke Catalan, a neo-Latin tongue. Galician, close to Portuguese, was used in Galicia, in the northwest corner of Spain. The Basques in northern Spain spoke Basque, a pre-Roman language unrelated to any other known tongue and using an ancient script. Bable, a form of Old Castilian was spoken in Asturias (northwest), and Valencian, a dialect of Catalan, was used by inhabitants of the eastern province of Valencia.