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.
La Franja
The Catalan language is spoken by a significant proportion of the population of La Franja (47.1% of the population uses it as their usual language according to a survey by the Aragonese Institute of Statistics in 2013; percentage that rises to 73.6%-90% according to two surveys carried out with a smaller territorial scope also in 2013 by the Generalitat of Catalonia) This despite the fact that it is not an official language and has a very limited presence in education (where it is only available as an elective) and in administration and or public acts, resulting in severe deficiencies in writing skills of this language.