Guarani
Guarani (avañe'ẽ), specifically the primary variety known as Paraguayan Guarani, is an indigenous language of South America that belongs to the Tupí–Guaraní 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 neighbouring 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, by a total of over 4 million speakers.
Guarani is distinguished by its rhythm, due to the avoidance of combinations between two consonants or two vowels and its regular prosody. It is also distinguished by its unique nasal harmony, with processes that make both consonants and vowels be nasalised.