Twenty vs Ten: HSE Researcher Examines Origins of Numeral System in Lezgic Languages
It is commonly believed that the Lezgic languages spoken in Dagestan and Azerbaijan originally used a vigesimal numeral system, with the decimal system emerging later. However, a recent analysis of numerals in various dialects, conducted by linguist Maksim Melenchenko from HSE University, suggests that the opposite may be true: the decimal system was used originally, with the vigesimal system developing later. The study has been published in Folia Linguistica.
How many fingers do you need to count to forty? That depends on the language you are counting in. In Russian and most European languages, the decimal counting system is standard, with numbers like 40 formed as 4 × 10, 60 as 6 × 10, and so on. A vigesimal system is based on the number 20, so 60 is expressed as 3 × 20, and 50 as 2 × 20 + 10.
Counting by tens or twenties is not just a matter of convenience—it also has historical roots. In the Lezgic group of languages—which includes Lezgian, Tabasaran, Aghul, and Rutul—both numeral systems are found: some dialects use a base-10 system with numbers like 10, 20, 30, while others follow a base-20 system with numbers like 20, 40, 60, and so on. Until recently, it was believed that the vigesimal system in these languages was more ancient, but a new study by linguists at HSE University challenges this assumption.
Maksim Melenchenko, Research Assistant at the Linguistic Convergence Laboratory of the HSE Faculty of Humanities, analysed numerals in nine Lezgic languages and concluded that the decimal system may have existed earlier, rather than being a later borrowing. In some languages, he discovered supposedly archaic forms of the number 40, suggesting an alternative development of the counting system. These forms are called archaic because certain features make them appear older than modern numerals.
Maksim Melenchenko
'For the number 40, some Lezgic languages unexpectedly use a decimal system: even in villages where counting by twenties is common, 40 is expressed as 4 × 10. This may indicate that the overall system of numeral formation has changed, but earlier forms of the number forty have persisted in the language, reflecting an older numeral system,' explains Melenchenko.
Another detail noted by the linguist is the special suffixes found on all decimal numerals from 30 to 90. In some languages where these numbers are formed decimally, they end with a suffix that originally indicated the grammatical gender of the noun the numeral refers to.
'This suggests that, in earlier times, the suffixes of decimal numerals actually changed to reflect grammatical gender. This implies that the decimal system was not a later introduction but had been in use long enough for gender markers in decimal numerals to become fossilised,' the linguist notes.
Dialectal variations in numeral systems can sometimes occur on opposite sides of the same mountain. For example, in the northern areas where Aghul is spoken, people count by tens, while in the southern parts, they count by twenties. Sometimes both systems coexist side by side: the older generation sticks to the traditional system, younger people use the more recent one, and some numerals reflect a mix of both systems.
Such variability shows how vibrant and dynamic different elements of a language—including numerals—can be. The study suggests that numeral systems can be easily borrowed, adapted, and changed spontaneously. Their history is not simply a progression from 'primitive' to 'advanced' structures, but a complex process that deserves close study—especially in linguistically rich and diverse regions like the Caucasus.
The study was conducted with support from HSE University's Basic Research Programme within the framework of the Centres of Excellence project.
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