Peru has the largest amount of Quechua speakers in South America (about 19% of the Peruvian population, or 4 million people). It was the official language of the Incas, although I think it’s interesting to note that they were not the ones who spread its use throughout South America. It 40+ different dialects were already popular before the Inca’s time.
The use of Quechua is shrinking as generations pass. It has always been more popular in the central highlands, where the Incas had their most extensive strongholds, and traditional life prevailed even after the Spaniards settled in the country. I think the integration of the highlands into the rest of Peru through tourism and commerce has been one reason for decline. There was also a mass migration that happened during the Shining Path Era that put Quechua speakers in the Coastal regions where Spanish was more popular.
Honestly, when I think of Quechua speakers, these traditionally dressed ladies that roam around the main square in Cusco come to mind. But as far as I know we haven’t come across anyone who speaks solely Quechua. The majority of the people we interact with are trying to sell us something, and they know Spanish (and sometimes enough English) to barter prices and make sales.
Some English words derived from Quechua: coca, condor, guano, gaucho, guanaco, Inca, jerky, lagniappe, lima [bean], llama, pampa, puma, quipu, quinine, quinoa, vicuña
