The language spoken in Buenos Aires, the capital of Argentina, is Spanish. However, it's worth noting that the Spanish spoken in Buenos Aires has some unique characteristics and features, which are distinct from the Spanish spoken in other regions of the Spanish-speaking world. Here's a description of the Spanish language in Buenos Aires:

Rioplatense Spanish: The variety of Spanish spoken in Buenos Aires is often referred to as "Rioplatense Spanish" or "Castellano Rioplatense." This term is derived from the Río de la Plata, the river that runs through Buenos Aires and separates Argentina from Uruguay. Rioplatense Spanish is distinct from other Spanish dialects in Latin America and Spain.

Pronunciation: One of the most notable features of Rioplatense Spanish is the unique pronunciation. Buenos Aires residents are known for their distinctive pronunciation of the Spanish "ll" and "y" sounds, which often sound like the "sh" or "zh" sounds found in English words like "measure" or "treasure." This pronunciation feature is known as "yeísmo."

Vocabulary and Phrases: Buenos Aires has a rich and distinct vocabulary with some words and phrases that are not commonly used in other Spanish-speaking regions. For example, the word "bondi" is often used to refer to a bus, while in other Spanish-speaking countries, it is usually called "autobús" or "autocar."

Lunfardo: Lunfardo is a jargon or slang language developed in Buenos Aires. It incorporates a mix of Italian, Spanish, and other influences. While not typically used in formal contexts, you may encounter Lunfardo in informal conversations or artistic expressions like tango lyrics.

Influence of Immigration: Buenos Aires has a history of immigration, particularly from Italy and other European countries, which has influenced the local language. As a result, you may find some Italian loanwords and phrases integrated into the local Spanish.

Formality: In Buenos Aires, people often use the informal second person singular "vos" form instead of the more formal "usted" when addressing someone in casual conversation. This is another characteristic of Rioplatense Spanish.

Clear and Articulate: Buenos Aires residents are known for their clear and articulate speech, which may be influenced by their strong emphasis on pronunciation.

Musicality: The Spanish spoken in Buenos Aires, especially when singing tango, is often described as having a certain musicality and rhythm that is characteristic of the city's cultural heritage.

In summary, the Spanish spoken in Buenos Aires, Argentina, has a distinctive pronunciation, vocabulary, and cultural influence, making it a unique and fascinating variety of the language. This regional dialect is an essential part of the city's identity and culture, adding to the charm and allure of Buenos Aires.