Languages of Catalonia
The main cause of Spanish and Catalan social bilingualism in modern Catalonia was large-scale migration from the rest of Spain during the 20th century, as Catalonia started a significant industrialization which demanded an increased workforce from elsewhere. Spanish has historically been spoken among a minority of civil servants born in other regions in Spain and among segments of the wealthiest bourgeoisie. Spanish has also been spoken as a second language by most Catalans, as it has been the only official language over long periods since the eighteenth century.
Languages of Catalonia
In this context, Catalan was the only language of instruction between 1979 and 2012. Thus, pupils were immersed in Catalan except for three hours per week of Spanish medium instruction. However, the most recent Spanish Education Law and some judicial sentences aim at increasing the time of instruction in Spanish for other subjects, if only one child per class asks it, even if the other families don't agree, because of complaints that current policies hinder the right to an education in Spanish.