Gramática de la lengua castellana ("Grammar of the Castilian language", also known as the Grammatica Nebrissensis, in 15th century Spanish,Grammatica dela Lingua Castellianna) is a book written by Antonio de Nebrija and published in 1492. It was the first work dedicated to the Spanish language and its rules.
Nebrija divided his study of the language into four books:
A fifth book was dedicated to the teaching of Castilian as a foreign language.
The book established ten parts of speech: nouns, pronouns, verbs, participles, prepositions, adverbs, interjections, conjunctions, gerunds and supines.
Works had previously been published on Latin usage, such as Lorenzo Valla's De Elegantiis Latinae Linguae (1471), but Grammatica was the first book to focus on the study of the rules of a Western European language besides Latin. Following its publication, grammar came to be considered as the discipline concerned with the rules of language, until the advent of linguistics as a scientific discipline in the 19th century.
Other grammars of the Spanish language followed: