It's important to note that:
* "Aztec" is a broad term. It often refers to the Mexica people, who were the dominant group in the Aztec Empire.
* Nahuatl was spoken by many different groups. It was the lingua franca of the central Mexican region, spoken by various groups besides the Mexica.
Today, Nahuatl is still spoken by many indigenous people in Mexico, making it one of the most spoken indigenous languages in the Americas.