Universitat Politècnica de Catalunya (UPC)

I understand just about any word, sentence or slang that the spanish can think of. In my spoken spanish I don't use that much slang because it's easier to talk without it. You simply speak faster when you don't need to think of some saying or slang every time you say a sentence. The only reason that I learned the language so well in such a short period is that I studied there and was in a class full of spanish(/catalan) people. Most of my friends were spanish(or spanish speaking) as well and all my other friends were there since september and already spoke the language quite well when I arrived. So I only had people I could learn from.

Barcelona is a bilingual town, and to be honest I would have to say that Catalan is the first language. Of course everyone understands and speaks Castellano (Spanish) perfectly, but quite a few people will (for political or other reasons) prefer Catalan. It is perfectly possible to live here without speaking or understanding a word of Catalan, but at least understanding it will certainly make you feel less of an alien. Studying at the UPC, you will certainly come across classes in Catalan, especially at the school I went to (ETSEIB - Industrial Engineers), which has about 90% of its classes in Catalan.

For me spanish is my born language, however courses were sometimes in Catalan, sometimes locals are crazy (extremely proud) about their language (Catalan). Few of them refuse to speak spanish, even when they know it, to speak Catalan. There are some serious independence issues going in Catalunya

Had all my courses in English since I have been doing a International Masters Programme. All other students had courses in Spannish, we were an exception.

As everybody speaks catalan, it was nice to learn it, you don't have to, though, as everybody speaks Spanish too, but still, it is a good experience.

I went to Barcelona to learn Spanish and I did. However most of the classes were in Catalan so don't expect to learn Spanish at the University!