Diego Collado (?-1638) was a Spanish Dominican who came to Japan in 1619, at a time when the persecution of Christians was becoming severe, and carried out missionary work in and around Nagasaki for a period of two years. His knowledge of the Japanese language was later put to good use when he published the present grammar, together with a Latin-Portuguese-Japanese dictionary, in 1632.
　　Collado explains in the preface to the work that one of the chief motives which prompted him to undertake it was the scarcity of copies of the grammar of Joa〜o Rodrigues (1561-1634), which had appeared some thirty years earlier. He goes on to explain some of the intricacies of Japanese pronunciation, and then the grammar proper begins with an exposition of the noun. This is followed in the traditional order by sections on pronouns, verbs, and a fairly comprehensive treatment of the syntax, with a note of the system of counting in Japanese at the end of the work.