SummaryThe paper explores three grammars of two indigenous languages of Brazil written in Portuguese during the colonial period: two grammars of the Tupi language composed by José Anchieta (1534–1597) in 1595 and Luís Figueira (1575–1643) in 1621 (2nd ed., 1687), and one grammar of the Kiriri language, written by Luis Vincêncio Mamiani (1652–1730) in 1699. Although most studies agree that these grammars were based on a Latin framework, they usually do not specify which grammar in particular served as a model. It is known, however, that the Latin grammar by Manuel Álvares (1526–1582), first published in 1572, became the main Latin school grammar for Jesuits all over the world. This article tries to give answers to questions such as why did the Jesuits favour this grammar, which grammars were used by them before 1572, how did the Portuguese missionaries in Brazil adapt or copy Álvares’ model, which parts of speech did they particularly use, and which definitions did they select and which elements did they discuss, add or omit?