During the colonial era, many Native Americans and mestizos adopted the Spanish language, and were converted to Roman Catholicism, the religion of the Spanish colonizers. As many as 100 Native American languages are still spoken in Mexico, but no single alternative language prevails.

Eighty percent of those Mexicans who speak an indigenous language also speak Spanish. The most important of the Native American languages is Nahuatl -- the primary language of more than a million Mexicans, and spoken by nearly one-fourth of all Native Americans in the country. This is followed by Maya, used by 14 percent of Native Americans. The Mexican government prefers to use language as its primary determinant when counting the number of Native Americans in the population.