"Classical Otomi" is the term used to define the Otomi spoken in the early centuries of colonial rule. This historical stage of the language was given Latin orthography and documented by Spanish friars who learned it in order to proselytize among the Otomi. Text in Classical Otomi is not readily comprehensible since the Spanish-speaking friars failed to differentiate the varied vowel and consonant phonemes used in Otomi. Friars and monks from the Spanish mendicant orders such as the Franciscans wrote Otomi grammars, the earliest of which is Friar Pedro de Cárceres's "Arte de la lengua othomí" , written perhaps as early as 1580, but not published until 1907. In 1605, Alonso de Urbano wrote a trilingual Spanish-Nahuatl-Otomi dictionary, which included a small set of grammatical notes about Otomi. The grammarian of Nahuatl, Horacio Carochi, has written a grammar of Otomi, but no copies have survived. He is the author of an anonymous dictionary of Otomi (manuscript 1640). In the latter half of the eighteenth century, an anonymous Jesuit priest wrote the grammar "Luces del Otomi" (which is, strictly speaking, not a grammar but a report on research about Otomi ). Neve y Molina wrote a dictionary and a grammar.