The Cuyo Spanish is the dialect

Dialect

The term dialect is used in two distinct ways, even by linguists. One usage refers to a variety of a language that is a characteristic of a particular group of the language's speakers. The term is applied most often to regional speech patterns, but a dialect may also be defined by other factors,...

 of Spanish

Spanish language

Spanish , also known as Castilian , is a Romance language in the Ibero-Romance group that evolved from several languages and dialects in central-northern Iberia around the 9th century and gradually spread with the expansion of the Kingdom of Castile into central and southern Iberia during the...

 that evolved in the historical province of Cuyo and that is now spoken in the Argentine provinces of Mendoza

Mendoza Province

The Province of Mendoza is a province of Argentina, located in the western central part of the country in the Cuyo region. It borders to the north with San Juan, the south with La Pampa and Neuquén, the east with San Luis, and to the west with the republic of Chile; the international limit is...

 and San Juan. To a lesser extent it is also spoken in the provinces of San Luis

San Luis Province

San Luis is a province of Argentina located near the geographical center of the country . Neighboring provinces are, from the north clockwise, La Rioja, Córdoba, La Pampa, Mendoza and San Juan.-History:...

 and La Rioja. The Cuyo Spanish shares a series of common traits with Chilean Spanish

Chilean Spanish

Chilean Spanish is the variety of Spanish spoken in most of Chile. Though still entirely mutually intelligible with standard Spanish, Chilean Spanish has distinctive pronunciation, grammar, vocabulary, and slang usage...

 due to settlement history and commercial ties. Later on, under the Argentine Republic Rioplatense Spanish

Rioplatense Spanish

Rioplatense Spanish or River Plate Spanish is a dialectal variant of the Spanish language spoken mainly in the areas in and around the Río de la Plata basin of Argentina and Uruguay, and also in Rio Grande do Sul, although features of the dialect are shared with the varieties of Spanish spoken...

, the dialect of Buenos Aires

Buenos Aires

Buenos Aires is the capital and largest city of Argentina, and the second-largest metropolitan area in South America, after São Paulo. It is located on the western shore of the estuary of the Río de la Plata, on the southeastern coast of the South American continent...

 and Uruguay

Uruguay

Uruguay ,officially the Oriental Republic of Uruguay,sometimes the Eastern Republic of Uruguay; ) is a country in the southeastern part of South America. It is home to some 3.5 million people, of whom 1.8 million live in the capital Montevideo and its metropolitan area...

influenced the Cuyo Spanish.