There are almost 70 indigenous languages in Mexico, many of which are still in use. However, Spanish is the de facto national language. Spanish is used by almost the entire population and all public communication (signs, documents, media, etc.) is in Spanish. Bilingual signs in Spanish and English may be present at popular tourist destinations.
English is understood by many people in Mexico City and also by some tourism staff in popular tourist destinations, but still most Mexicans do not speak English. Educated Mexicans, especially younger ones, and professional business people are most likely to speak some English. After English, the most popular foreign languages to learn in Mexico are French, Italian, German and Japanese. German, French and Russian may be familiar to some in the tourism industry, but among office workers, police officers and drivers (especially the latter) foreign language skills are virtually non-existent.
Mexico has one of the greatest linguistic diversity: more than 60 indigenous languages are spoken on Mexican territory. These languages are spoken in the communities of these indigenous peoples, which are largely separated from the dominant mestizo society. In any case, the chances of finding a speaker of one of these languages are slim, since only half of the 20% of the indigenous population in Mexico speaks an indigenous language. On the other hand, most of these communities also speak fluent Spanish. Therefore, learning one of these indigenous languages is by no means essential; on the contrary, it is unexpected and will gain much respect from these communities.