Here's a breakdown:
* Catalan: The official language of Catalonia, the region where Barcelona is located. It's spoken by a majority of the population in the city.
* Spanish: The official language of Spain, and also very common in Barcelona. Most people in Barcelona are bilingual in Catalan and Spanish.
* Other Languages: You may also encounter some English, French, or other languages spoken by tourists and immigrants.
So, while Catalan is the official language, it's safe to assume that most people in Barcelona will understand Spanish, and many will speak English as well.