Proto-Indo-European numerals


The numerals and derived numbers of the Proto-Indo-European language have been reconstructed by modern linguists based on similarities found across all Indo-European languages. The following article lists and discusses their hypothesized forms.

Cardinal numbers

The cardinal numbers are reconstructed as follows:
NumberReconstruction Reconstruction
one
two
three ' / '
four ' / '
five
six; originally perhaps
seven
eight, or,
nine
ten
twenty; originally perhaps
thirty; originally perhaps
forty; originally perhaps
fifty; originally perhaps
sixty; originally perhaps
seventy; originally perhaps
eighty; originally perhaps
ninety; originally perhaps
hundred; originally perhaps
thousand;

Other reconstructions typically differ only slightly from Beekes and Sihler. A nineteenth-century reconstruction for thousand is. See also Fortson 2004.
The elements and are reconstructed on the assumption that these numerals are derivatives of *deḱm̥ "ten".
Lehmann believes that the numbers greater than ten were constructed separately in the dialect groups and that originally meant "a large number" rather than specifically "one hundred."

Gender of numerals

The numbers three and four had feminine forms with the suffix, reconstructed as and, respectively.

Numerals as prefixes

Special forms of the numerals were used as prefixes, usually to form bahuvrihis :
NumberPrefix
one-
two-
three-
four- or

Ordinal numbers

The ordinal numbers are difficult to reconstruct due to their variety in the daughter languages. The following reconstructions are tentative:
The cardinals ending in a syllabic nasal inserted a second nasal before the thematic vowel, resulting in the suffixes and. These and the suffix spread to neighbouring ordinals, seen for example in Vedic aṣṭamá- "eighth" and Lithuanian deviñtas "ninth".

Reflexes

, or descendants of the PIE reconstructed forms in its daughter languages, include the following.

Reflexes of the cardinal numbers

In the following languages, reflexes separated by slashes mean:

Reflexes of the numeral prefixes

Reflexes of the ordinal numbers