Lengua X: An Andean Puzzle

In the south-central Andes, several researchers have documented series of numerical terms that some have attributed to a hitherto unknown language: Lengua X. Indeed, they are difficult to link, as a whole, with numerical series from the known languages of the area. This paper discusses the available information on these series and attempts to trace their origin. It is difficult to argue that they are the remnants of a single, vanished language. Instead, it is argued that Lengua X numbers for ‘one’ and ‘two’ originate in Aymara, a language from the highlands, whereas terms for ‘three’ to ‘five’ originate in Mosetén, a language from the eastern foothills. Additional parallels with Uru-Chipayan, Quechua, and Aymara (terms from ‘six’ to ‘ten’) suggest that Lengua X numbers reflect a unique and complex situation of language contact in the south-central Andes.