User:Jose Fernandez-Calvo/Argentine, not Argentinian

The official, and grammatically correct, demonym for Argentina is Argentine.

It is the official use because it has uniformly been used this way by the Argentine Government, including all international treaties signed by the Argentine Republic. No treaty has every been signed by the "Argentinian Republic".

It is the grammatically correct use because, in Spanish, the country is called "Republica Argentina", not "Republica de Argentina". The missing "de" signals the use of Argentina as an adjective, not a noun, which makes both the Argentinian and Argentinean usages flat out wrong.

Argentinian and Argentinean are often misused, even by Argentines themselves. The fact that several dictionaries say that both Argentinian and Argentinean are accepted usages is an indictment on them, not an indication that those usages are correct.