My specialist topic! Quite a lot of similarities between Catalan and Scots in terms of the linguistic ‘distance’ from their dominant neighbours. Spanish speakers moving to Catalonia can understand most of it very quickly and learn to speak it in weeks or months. Big differences are that Catalan is the major carrier of Catalan identity and of course it is spoken by the middle classes, that is really why it has “survived”. Interestingly it was standardised as recently in 1913, about the same time Scots was also being properly documented. Like Scots, the urban dialect (mainly of Barcelona) is considered corrupted, and Catalan school teachers make a lot of effort weeding out Spanish ‘barbarisms’ and and preventing ad hoc Catalan-Spanish mixing (‘catanyol’). Valencian and Mallorquin are considered separate languages but the mainstream versions are linguistically almost identical to Catalan and almost fully comprehensible.
Catalan is not, as some believe, a dialect of Spanish, but a language that developed independently out of the vulgar Latin spoken by the Romans who colonised the Tarragona area. It is spoken by 9 million people in Catalonia, Valencia, the Balearic Isles, Andorra and the town of Alghero in Sardinia.