Learn Spanish
as it's spoken on the street.

Spanish is not one dialect wearing five different accents. Mexico City, Madrid, Barcelona, Buenos Aires, and Medellín each have their own vocabulary, their own pronunciation rules, and their own social register, and the gaps between them are bigger than most learners expect going in.

Mexico City Spanish (Chilango) is often called one of the clearest, most neutral dialects in Latin America, and the vowels really are consistent and easy to parse. But clear is not the same as textbook. Güey shows up in almost every casual sentence between friends without being an insult. Ahorita does not mean right now, it means sometime relatively soon, or possibly not soon at all, and only context tells you which. And a layer of Náhuatl vocabulary (jitomate, elote, aguacate, chapulín) sits underneath everyday food and market conversation that no generic course ever teaches.

Madrid speaks Castilian Spanish, the variety most people mean when they say Spain Spanish: the c and z pronounced as a soft th, vosotros as the standard plural you, and a fast, direct, loud conversational style that many Latin American speakers find blunt at first. It is the closest thing to a national standard, and it sounds nothing like Mexico City.

Barcelona complicates the picture further. The city is genuinely bilingual, and the Spanish spoken there carries Catalan phonology: cleaner vowels, a different melodic pattern, and Catalan vocabulary that bleeds into everyday Castilian conversation. Someone who learns Madrid Spanish and lands in Barcelona will be understood, but the accent and vocabulary will both feel like they belong to a different city, because they do.

Buenos Aires breaks from the pattern entirely. Rioplatense Spanish uses vos instead of tú, with its own conjugation, pronounces ll and y as a sh sound (calle sounds like ca-she, not ca-yeh), and carries a melodic, Italian influenced intonation from a century of Italian immigration. Add lunfardo, the city's own slang system, and porteño Spanish is arguably the most distinctive dialect in the Spanish speaking world.

Medellín adds a third pronoun system on top of that. Paisa Spanish mixes usted (used even with close friends, a genuine hallmark of paisa speech), vos (used between friends and family), and the least common of the three, tú. Layer in a warm, singsongy cantado rhythm and a distinct slang vocabulary (parce, bacano, chévere), and Medellín sounds unmistakably like nowhere else.

Five cities, one language on paper, five different things to actually learn. Pick the city you are headed to and start there. The other dialects will make more sense once you have one of them solidly under you, not the other way around.