Henri, there are no schools in Argentina where English is the first language, in some expensive schools they give much importance to English and sometimes they learn some other language too, but i assure you that argentinian teens can barely speak Spanish. Maxima must have taken English lessons somewhere else, even when she was at the University.
I know this is an old thread but I had to comment on some of the things being said.
I attended Northlands School from Kindergarten through Secondary School (in total, 14 years). It is not correct to say that there are no schools in Argentina in which English is the first language because I can assure you that at Northlands, it is. We are taught English and Spanish simultaneously from an early age, becoming fluent very early on. At Primary School, in order to comply with the National Curriculum, in the morning lessons were conducted in english; in the afternoon lessons were conducted in spanish.
At the age of 12 we moved on to Secondary School, where 12 out of 14 annual classes were taught in english (with the exception of Spanish Lit and Argentine History or Geography). This is because Northlands is not a Bilingual School but rather an English School. During recess we spoke in english. Even P.E. was conducted in english. By the time I was 15 I only had one class in Spanish. At 11 I was already bilingual to the point where I think in English and feel more comfortable expressing myself in that language. We take IGCSEs in Year 10 and IBOs in Year 12, another reason why English is taught as a First Language.
Someone said Northlands is all about sports... another wrongful judgement based on absolutely no knowledge of this School. At Northlands we were taught to aim high and succeed, and this involved Sports, Languages, Academics, Arts, Sciences, Music, etc. Interschool Sports Competitions are important, but Academics are even more so.
The reason why Maxima has no accent when speaking english, or why her vocabulary and command of the language is outstanding, is because of her school.