This article is intended as a contribution to the history of Spanish grammar of the 16th and 17th centures. It has two parts. In the first the author places grammar studies within the framework of Spanish linguistics of the Renaissance; in the second, he delineates their evolution with reference to Latin grammar and the teaching Spanish as a foreign language. It is well known that nationalism and the intention to establish the literary foundations of the language are the most important agents of grammatical studies during the Renaissance; yet, attention must also be paid to the rupture of medieval Latin-Romance bilingualism, to the new intellectual paradigm in which rhetorics substitutes for syllogism, and to the influence of Erasmus. The grammar of the troubadours and Latin grammar – medieval and humanist – evoke an interest in developing grammars of Romance languages; it made the appearance of Nebrija possible. In his grammar of Spanish we may stress its capacity to be a grammar for foreigners and the value of this document for the history of Spanish. Spanish grammar writing of the 16th century is dominated by Nebrija; is strong presence is evident with the critical reception Villalon and Valdes give to his work. In the 17th century the work of Sanctius initiates a rationalism which favours pedagogical methodology and linguistic nationalism. Jimenez Paton, Correas and Caramuel are the most important authors of that period. With an exemplary linguistic realism Correas applies Sanctius’ theory of the elipsis to Spanish, and he recognizes the singularity of Spanish grammar in contrast to that of Latin. The grammars written for foreigners in the 17th century are at the height of inductive methodology.