Guarani ( or ), specifically the primary variety known as Paraguayan Guarani (endonym avañe'ẽ 'the people's language'), is an indigenous language of South America that belongs to the Tupi–Guarani subfamily of the Tupian languages. It is one of the official languages of Paraguay (along with Spanish), where it is spoken by the majority of the population, and where half of the rural population is monolingual. It is spoken by communities in neighboring countries, including parts of northeastern Argentina, southeastern Bolivia and southwestern Brazil, and is a second official language of the Argentine province of Corrientes since 2004; it is also an official language of Mercosur.