Both spellings, Cusco and Cuzco, are valid and accepted by the Royal Spanish Academy (RAE), but they are used differently: Cusco (with an S) is the official and preferred spelling in Peru (derived from the Quechua word Qosqo), while Cuzco (with a Z) is more common in the rest of the Spanish-speaking world and Spain.
Which one to use?
In Peru: Use Cusco. It is the official, constitutional, and preferred spelling by locals, who write the original Quechua name (Qosqo) with an "S".
In other Spanish-speaking countries: You can use Cuzco, as it is the most widespread and recognized spelling in most countries, explains FundéuRAE and Depor.
In academic or international contexts: Both are valid, although Cuzco was historically used to represent the pronunciation of the time, notes BBC News Mundo.
Cuzco or Cusco?
On its website, the Cusco regional government defends the spelling with an "S" because the city's name "derives from the Quechua word Qosqo".
Furthermore, it is worth remembering that "this is mandated by law," following a 1986 ministerial resolution signed by the then Minister of Education of Peru, which officially established the spelling of "Cusco" and stipulated that all entities within the education sector apply it.
The Peruvian Constitution also adheres to this criterion, stating in Article 49 that the historical capital of the country is "the city of Cusco."
Thus, although "Cuzco" was historically the spelling for centuries, the tendency to use the "S" has overwhelmingly prevailed in Peru for years.
One of the most widespread theories against "Cuzco" is that the Incas did not know the "Z," but rather that this spelling was imposed by the Spanish conquistadors, who pronounced it with the characteristic "Z" sound used today in most of Spain.
But experts say that this interdental pronunciation was not the predominant one among the explorers who arrived in the "New World," most of whom came from southern Spain where the "Z" sound is much more similar to how it is pronounced in Latin America.
"The alphabet used in Spanish was unknown to the Incas. That argument doesn't hold water at all; it has nothing to do with how the Quechua people pronounced it, and we don't even know if they had a writing system," Marco Martos, president of the Peruvian Academy of Language, told BBC Mundo.
Rodolfo Cerrón Palomino, a member of the Peruvian Academy of History and a linguist specializing in Andean languages, agrees, stating that "at the time of the conquest, the Spanish used the 'Z' and the 'Ç' as two letters that represent the dorsal 'S,' that is, the Andalusian 'S' or the Latin American 'S.'"
Therefore, the language scholar also asserts that there was no error in how the conquistadors adapted Qosqo, but rather that the "Z" of that era (more aspirated and different from the current pronunciation in Spain) was the most accurate way to imitate what they heard from the indigenous peoples.
"What would happen to Mexicans if they replaced the 'X' with a 'J' in their country's name? They have made the 'X' prevail, and for them it's like a flag, a symbol of identity. We should adopt something like this if we had any cultural and historical awareness," he tells BBC Mundo.
Cerrón Palomino, who admits to being "a Quixote fighting" against the predominant use of the "S" in his country, calls it an "absurd argument" that "Cuzco" is also avoided because this word means "small dog" according to the Royal Spanish Academy dictionary, even though this meaning is not used in the country.
The truth is that both spellings for this city are so popular that even the Royal Spanish Academy (RAE) states that "both forms are equally valid," although "Cusco" is preferred in Peru and "Cuzco" is more widespread in other Spanish-speaking countries, according to the Pan-Hispanic Dictionary of Doubts.
A Google search confirms the historical use of "Cuzco," yielding significantly more results than the spelling with "S." However, "Cusco" is a more common term used by users when searching, both in Peru and worldwide.
Will this be the trend in how to spell it in the future?
