Nahuatl orthography is the body of methodologies and conventions used to express the Nahuatl languages and dialects in some given writing system, and the inventory of glyphs, graphemes and diacritics employed for that purpose.
Historically Nahuatl has been written with greatly differing orthographies because no institution has governed its spelling. This is still true for the classical dialect (Classical Nahuatl) which is a dead language documented in many historical sources and literature, but spelling of the modern dialects of Nahuatl is governed by the Mexican Secretaría de Educación Publica (federal education ministry), although they do have some difficulties in implementing their orthographic standards in the Nahuatl communities.
This article describes and compares some of the different transcription systems of the Nahuatl phonological system that have been used.
Vowels come in long and short pairs.
At the time of the Spanish conquest, Aztec writing used mostly pictographs supplemented by a few ideograms. When needed, it also used syllabic equivalences; Father Diego Durán recorded how the tlàcuilòquê (codex painters) could render a prayer in Latin using this system, but it was difficult to use. This writing system was adequate for keeping such records as genealogies, astronomical information, and tribute lists, but could not represent a full vocabulary of spoken language in the way that the writing systems of the old world or of the Maya civilization could. The Aztec writing was not meant to be read, but to be told; the elaborate codices were essentially pictographic aids for teaching, and long texts were memorized.