Here's why:
* Nahuatl was the language of the dominant group: The Mexica, who founded the Aztec Empire, spoke Nahuatl. It became the language of administration, trade, and diplomacy across the empire.
* Other languages existed: However, numerous other languages were spoken throughout the Aztec Empire. Estimates suggest over 100 different languages were used by the various indigenous groups.
* Nahuatl's legacy: Today, Nahuatl is still spoken by millions of people in Mexico, primarily in the central and southern regions.
While Nahuatl is often referred to as *the* Aztec language, it's important to remember the cultural and linguistic diversity that existed within the empire.