Aztec writing had three primary functions, namely to mark calendrical dates, to record accounting mathematical calculations, and to write names of people and places. No continuous texts like those of the Maya or Olmec writing system has been be found.
The writing system of the Aztecs is very rudimentary. Its core consists of a set of calendrical signs and a number system. Like other Mesoamerican people, the Aztecs used the 260-day sacred calendar, which in Nahuatl (Aztec) was called tonalpohualli. The tonalpohualli is essentially two parallel and interlocking cycles, one of 20 days (represented by "day signs"), and one of 13 days (represented by numbers called "coefficients"). The following are the 20 day signs in the Aztec sacred calendar. The Nahuatl names are in red, and their meanings in English are in blue.
The Aztecs had a 365-day solar calendar called xiuhpohualli, which consisted of 18 months of 20 days, and an unlucky 5-day period at the end of the year. However, they rarely recorded dates in the solar calendar on manuscripts, and never on monuments.
In addition, like other Mesoamerican cultures, the Aztecs also employed the Calendar Round, a 52-year period created by interlocking the 260-day and 365-day cycles. A year in the Calendar Round was named by the tonalpohualli name of last day of the last month in the xiuhpohualli for that year. Because of the way the math worked out, only four day signs, namely Calli, Tochtli, Acatl, and Tecpatl, could be part of a year's name, and hence they were called "year bearers". Accompanying the year bearers were coefficients, which could range from 1 to 13. To distinguish Calendar Round years from days in the 260-day calendar, years glyphs were drawn inside rectangular "cartouches". A good example occurs in the Codex Telleriano-Remensis, a document written after the Spanish Conquest but at a time when knowledge of the pre-Columbian culture was still available. In this document, Aztec years are correlated to Western Gregorian years.
The following is a small set of toponyms (place names) as found in various post-Conquest manuscripts. The first set of examples are names spelled out mostly by pictorial logograms.
Explanations for the previous example:
- Chilapan, from chilli + apan, meaning "at the water of chiles". The picture of a chile pepper provides the first root chilli, while the ending apan, meaning "place of water", is provided by water in a canal.
- Colhuacan, from colhua + can, meaning "twisted or crooked hill". Clearly illustrated by the twisted hill top.
- Ocelotepec, from ocelotl + tepec, meaning "hill of the ocelot". The ocelot is wildcat common to the Americas and is depicted here by its head. Also, in Nahuatl, can is synonymous with tepec, and hence both words are represented by the same sign.
- Coatlan, from coatl + tlan, meaning "place abundant with snakes". Here we encounter the first example of using phonetic elements. Teeth in Nahuatl is tlantli, and so a set of teeth is conventionally read as tlan, which is a Nahuatl suffix meaning "place abundant with".
- Coatzinco, from coatl + tzin + co, meaning "little Coatlan". The ending tzinco is represented phonetically by the lower half of a crouching man, which in reality carries the meaning of 'buttocks'. The word 'buttocks' in Nahuatl is tzintli, and conveniently spells out the syllable tzin.
- Ahuacatlan, from ahuacatl + tlan, meaning "place abundant with avocadoes". Once again the ending tlan is represented by a set of teeth, but this time incorporated into the avocado tree.
- Capulteopan, from capulli + teopan, meaning "the temple of the neighborhood". The word "temple", teopan, is clearly depicted, but "neighborhood", capulli is harder to visualize. Rebus writing comes to the rescue in that capulli is phonetically similar to capulin, which is a Mexican plant related to cherries. By drawing the capulin tree, the sound capul is expressed.
- Mapachtepec, from mapach + tepec, meaning "near the hill of the raccoon". Instead of drawing a raccoon, mapach in Nahuatl, a hand (maitl) and a piece of moss (pachtli) are drawn together. By taking the first syllables of both words, /ma/ and /pach/, we obtain mapach.
- Miacatla, from mitl + aca + tla(n), meaning "place abundant with arrows". The picture of an arrow, mitl logographically represents the first part of the word. The ending, acatla, is provided phonetically by the depiction of a reed, acatl in Nahuatl.
- Amacoztitlan, from amatl + cozti + tlan, meaning "place abundant with yellow papers". The concept of a yellow paper is expressed in the yellow rectangular in the middle of the signs. Water, atl, on the bottom is used phonetically to provide the initial vowel /a/, reinforcing the reading of "amacoztli". The set of teeth on the top phonetically provide the ending tlan.
- Pantepec, from pan + tepec, meaning "upon the hill". The particle pan carries the meaning of "above" or "upon", which is depicted by the picture of a flag, pantli in Nahuatl.
- Tepechpan, from tepexitl + pan, meaning "above the crag". The phonetic elements consist of tetl and petlatl, which together approximates the initial tepech. The final syllable pan is indicated figuratively by placing a house above the tepech component at the bottom, effectively giving the reading of "above the crag".
Signs used for phonetic values are not randomly drawn from the logograms but actually from a very predictable and minimal set. But, most of all, since the knowledge of the underlying language, Nahuatl, is essential to fully interpret the glyphs, the Aztec script most certainly classifies as a writing system.
Despite the limitation of their writing systems, the Central Mexicans must have produced countless numbers of manuscripts with subject matters as diverse as time-keeping, astronomy and astrology, mythology, genealogy, and history, all attesting to the power of the written word.
The toponyms in the previous examples were taken from Nombres Geográficos de México project website.