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.
Valencian
Valencian ( or ; endonym: "valencià", "llengua valenciana", or "idioma valencià") is the traditional, historical and cultural linguistic variety of Catalan spoken in the Valencian Community, Spain. It's officially recognised as a language in the Statute of Autonomy of the Valencian Community signed in 1982 and approved by the Valencian regional government and the Spanish government. In the Valencian Community, Valencian is the traditional language and is co-official with Spanish. A standardized form exists, based on the Southern Valencian dialect.