PhoneTelcel and Movistar are the main mobile operators in Mexico. If you have an unlocked GSM phone, you can buy a prepaid SIM card. If you have an iPhone, you should purchase a package of data with ROAMFREE Mobile, as pay-as-you-go internet is extremely expensive. If you're staying for over a week and don't have a unlocked phone, it might be a good idea to buy a cheap handset and buy a prepaid card.
You can also call from public phones using prepaid tel. The rate to call the US is roughly equivalent to USD0. 50 per minute. Cards can be bought at magazine stalls and convenience stores.
LanguageMexico doesn't have an official language at federal level, but there is the most populous Spanish-speaking country in the world. Spanish is used by virtually the whole population and all public communications are conducted in the language. Bilingual signs in Spanish and English might be available in popular tourist destinations. The other 67 are indigenous languages that, although officially recognized, people almost never speak.
English is understood by many in Mexico City as well as by some tourist workers in popular tourist places, but nevertheless, most Mexicans don't speak English. Educated Mexicans, especially younger ones, and professional businessmen are the people most likely to speak some English. The most popular foreign languages to learn within Mexico after English are French, Italian, German and Japanese.