Funny language-related confession here: I often forget that "de res" and "adéu" are Catalan. I don't speak Catalan at home or anywhere outside of my school really, but I've gotten used to utilizing "de res" (Catalan for "you're welcome") and "adéu" (Catalan for "goodbye") in Spanish conversations. Hell, I've straight up replaced my "adiós" for "adéu" because it sounds more friendly according to my brain. It's when I hear a non-Catalan Spanish-speaking person respond to an "adéu" of mine with an "adiós" or to a "gracias" with a "de nada" that I remember that those expressions aren't actually Spanish, but Catalan. I also tend to use "T'estimo" (Catalan for "I love you") instead of "Te quiero" (Spanish for "I love you") when I'm talking to my family but I'm aware that that is a Catalan expression.
Bonus Catalonia fun fact: Some Catalan people use "Merci" (French for "Thank you") instead of "Gracias" (Spanish for "Thank you") or "Gràcies" (Catalan for "Thank You"). I don't, but enter a store here and you'll hear a lot of "Merci"s. I'm unsure whether this does or does not happen in other parts of Spain, though.















