Portuguese is the third most spoken language of the Americas, and the second most spoken language in South America. It is the sole official language of Brazil and is a co-official language of several regional organizations, notably Mercosul, UNASUL, ACTO, CELAC, the Rio Group, and ALADI. The main varieties of Portuguese spoken in South America are Brazilian Portuguese (spoken by the vast majority), Uruguayan Portuguese and a mixed variety known as Portuñol/Portunhol.