Spanish is the official language, but English is widely spoken at tourist offices, airlines, travel agencies, upscale hotels, and in business settings. In the provinces it’s less common, though its use is spreading, especially in the travel and tourism sector.
Foreign-language use is also vigorous among ethnic communities such as Italo-Argentines, Anglo-Argentines, and German-Argentines. The Anglo-Argentine and business communities even support a daily tabloid, the Buenos Aires Herald, while the German-Argentine community has the weekly Argentinisches Tageblatt. Welsh is making a comeback in Chubut Province.
Buenos Aires [1] also has its own street slang, lunfardo, which owes its origins to working-class immigrant communities. Many lunfardo words have worked their way into everyday Argentine speech even though they may be unintelligible to those who have learned Spanish elsewhere. Some are fairly obvious in context, such as laburar instead of trabajar for work or labor, but others are obscure.
While many of its idioms are crude by standards of formal Spanish, lunfardo has acquired a certain legitimacy among Argentine scholars. There is even an academy for the study of porteño slang, the Academia Porteña del Lunfardo (Estados Unidos 1379, Monserrat, Buenos Aires, tel. 011/4383-2393, www.aplunfardo.org.ar [2]).
Links:
[1] http://www.moon.com/destinations/argentina/buenos-aires
[2] http://www.aplunfardo.org.ar