Peru, like many South American nations, has Spanish as its official language. It’s a good idea to learn a few basic Spanish phrases since you’ll need them to travel about outside of the major tourist areas. Although English is spoken by a growing number of young people in Lima and, to a lesser degree, in the most prominent tourist destinations, it is much less widely understood than you would think in a country where tourism is such a major business.
Learning some Quechua or Aymara, especially if you’re on your own, may open opportunities, since indigenous people would respect your effort. Quecha is the language of the Incas and the first language of many indigenous peoples in the Sierra Nevada region. The Tihuanacu culture’s language was Aymara, which is widely spoken in the Altiplano. However, in both situations, individuals will usually speak English as well.