# Proto-Indo-European numerals

The numerals and derived numbers of the Proto-Indo-European language (PIE) 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:
| Number | Reconstruction (Sihler) | Reconstruction (Beekes) |
| one | *Hoi-no-/*Hoi-wo-/*Hoi-k(ʷ)o-; *sem- | *Hoi(H)nos ; sem-/sm̥- |
| two | *d(u)wo- | *du̯oh₁ |
| three | *trei- (full grade) / *tri- (zero grade) | *trei̯es |
| four | *kʷetwor- (o-grade) / *kʷetur- (zero grade) (see also the kʷetwóres rule) | *kʷétu̯ōr |
| five | *penkʷe | *penkʷe |
| six | *s(w)eḱs; originally perhaps *weḱs | *(s)u̯éks |
| seven | *septm̥ | *séptm̥ |
| eight | *(h₁)oḱtṓw or *h₃eḱtō, *h₃eḱtow | *h₃eḱteh₃ |
| nine | *(h₁)newn̥ | *(h₁)néun |
| ten | *deḱm̥(t) | *déḱm̥t |
| twenty | *wīḱm̥t-; originally perhaps *widḱomt- | *du̯idḱm̥ti |
| thirty | *trīḱomt-; originally perhaps *tridḱomt- | *trih₂dḱomth₂ |
| forty | *kʷetwr̥̄ḱomt-; originally perhaps *kʷetwr̥dḱomt- | *kʷeturdḱomth₂ |
| fifty | *penkʷēḱomt-; originally perhaps *penkʷedḱomt- | *penkʷedḱomth₂ |
| sixty | *s(w)eḱsḱomt-; originally perhaps *weḱsdḱomt- | *u̯eksdḱomth₂ |
| seventy | *septm̥̄ḱomt-; originally perhaps *septm̥dḱomt- | *septm̥dḱomth₂ |
| eighty | *oḱtō(u)ḱomt-; originally perhaps *h₃eḱto(u)dḱomt- | *h₃eḱth₃dḱomth₂ |
| ninety | *(h₁)newn̥̄ḱomt-; originally perhaps *h₁newn̥dḱomt- | *h₁neundḱomth₂ |
| hundred | *ḱm̥tom; originally perhaps *dḱm̥tom | *dḱm̥tóm |
| thousand | *ǵʰeslo-; *tusdḱomti (originally "big hundred") | *ǵʰesl- |
Other reconstructions typically differ only slightly from Beekes and Sihler. A nineteenth-century reconstruction (by Brugmann) for thousand is *tūsḱmtiə. See also Fortson 2004.
The elements *-dḱomt- (in the numerals "twenty" to "ninety") and *dḱm̥t- (in "hundred") are reconstructed on the assumption that these numerals are derivatives of *deḱm̥(t) "ten".
Lehmann believes that the numbers greater than ten were constructed separately in the dialect groups and that *ḱm̥tóm originally meant "a large number" rather than specifically "one hundred."
| PIE | English | Gothic | Latin | Ancient Greek | Sanskrit | Iranian | Slavic | Baltic | Celtic | Armenian | Albanian | Tocharian | Hittite |
| *sem- "one, together" | same (< ON samr); OE sam- "together"; [also German zusammen] | sama "same" | sem-el "once", sem-per "always", sim-plex "single, simple", sin-gulī "one each, single" | heĩs, hén, mía "one" < *sems, *sem, *smiH₂ | sam- "together", samá "same, equal, any" | Av hama-, OPers hama- "any, all" Past sam "even, fine" | OCS samŭ "self, alone, one" | Lith sam-, są- "with"; OPrus sa-, sen- "with, dividing" | OIr samlith "at the same time"; W hafal "equal" | mi "one" | gjithë “all” < PAlb *semdza | A sas, B ṣe "one" < *sems | |
| *(h₁)óynos, (h₁)óywos "one" | one (< OE ān) | ains "one" | ūnus (archaic oinos) | oĩnos "one (on a die)", oĩ(w)os "alone" | (ēka- < *oi-ko-; Mitanni-Aryan aika-vartana "one turn (around a track)") | Av aēva-, OPers aiva-, (NPers yek- "one, only, alone") | OCS inŭ "one, another" | Lith víenas, OPrus ains "one" | OIr ōen, W un "one" | andr-ēn "right there", ast-ēn "right here" | ? Gheg tânë, Tosk tërë "all" < PIE *tod-oino-; ??? një "one" < *ňân < PIE *eni-oino- | B -aiwenta "group" < "*unit" | ās "one" |
| *dwóh₁ , neut. *dwóy(H₁) "two" | two (< OE twā) | twái (fem. twōs, neut. twa) "two" | duo "two" | dúō "two" | dvā́(u) "two" | Av dva, fem. neut. baē "two"; NPers do "two"; Kurd diwa "two (fem.)" | OCS dŭva "two" | Lith dù, OPrus dwai "two" | OIr da, W dau (fem. dwy) "two" | erku "two" | dy "two" | A wu, B wi "two"(<PTC *tuwó) | dā-, ta-; HLuw tuwa/i- "two"; Lyc kbi- "two"; Mil tba "two" |
| *tréyes (fem. *tisres, neut. *tríH₂) "three" | three (< OE þrīe) | þreis "three" | trēs "three" | treĩs "three" | tráyas (fem. tisrás) "three" | Av θrayō, θrayas (fem. tisrō, neut. θri), OPers çi-, Parth hrē "three" | OCS trĭje "three" | Lith trỹs, OPrus tris, Latg treis "three" | OIr trí (fem. téoir), W tri (fem. tair, teir) "three" | erekʿ "three" | tre masc., tri fem. "three" | A tre, B trai "three" | tri- "three"; teriyas- (gen. pl.) |
| *kʷetwóres (fem. *kʷétesres, neut. *kʷetwṓr) "four" | four (< OE fēower) | fidwor "four" (In Germanic influenced by pénkʷe "five") | quattuor "four" | téssares "four" | masc. catvā́ras (acc. catúras), neut. catvā́ri, fem. cátasras "four" | Av masc. čaθwārō (acc. čaturąm), fem. čataŋrō "four"; NPers čahār "four"; Kurd çwar | OCS četyre "four" | Lith keturì, OPrus ketturei "four" | Gaul petuar[ios] "four" OIr ceth(a)ir (fem. cethēoir, influenced by fem. tēoir "three") "four"; W pedwar (fem. pedair) "four" | čʿorkʿ, kʿaṙ (rare) "four | katër "four" | A śtwar, B śtwer "four" | (remodelled in Hittite and Luwian) Lyc Teteri |
| *pénkʷe "five" | five (< OE fīf) | fimf "five" | quīnque "five" | pénte "five" | páñca "five"; Mitanni-Aryan panza- "five" | Av panča "five"; Kurd pênc/pênz | OCS pętĭ "five" | Lith penkì, OPrus penkei "five" | Gaul pinpe-, pompe "five" OIr cóic, W pum(p) "five" | hing "five" | pesë "five" | A päñ, B piś "five" | Luw paⁿta "five" |
| *swéḱs "six" | six (< OE siex) | sáihs "six" | sex "six" | héx, dial. wéx "six" | ṣáṣ "six" | Av xšvaš "six" | OCS šestĭ "six" | Lith šešì, OPrus uššai "six" | Celtib sues "six"; Gaul suexos "sixth"; OIr sé, W chwe(ch) "six" | vecʿ "six" | gjashtë "six" | A ṣäk, B ṣkas "six" | |
| *septḿ̥ "seven" | seven (< OE seofon) | sibun "seven" | septem "seven" | heptá "seven" | saptá "seven"; Mitanni-Aryan šatta- "seven" | Av hapta, NPers haft-, "seven" | OCS sedmĭ "seven" | Lith septynì, OPrus septinnei "seven" | OIr secht, W saith "seven" | eawtʿn "seven" | shtatë "seven" | A ṣpät, B ṣukt "seven" | sipta- "seven" |
| *h₁oḱtṓ(w) "eight" | eight (< OE eahta) | ahtáu "eight" | octō "eight" | oktṓ "eight" | aṣṭā́(u) "eight" | Av ašta "eight" | OCS osmĭ "eight" | Lith aštuonì, OPrus astonei, Latg ostoni "eight" | Gaul oxtu- "eight" OIr ocht n- "eight"; W wyth "eight" | utʿ "eight" | tetë "eight" < *H₁ok̂tō-t- | A okät, B okt "eight" | Lyc aitãta "eight" |
| *(h₁)néwn̥ "nine" | nine (< OE nigon) | niun "nine" | novem "nine" | ennéa "nine" | náva "nine" | Av nava, NPers noh- "nine" | OCS devętĭ "nine" < *newn̥-ti- (Influenced by dékm̥t "ten") | Lith devynì (influenced by dékm̥t "ten"), OPrus newinei "nine" | OIr noí n-, W naw "nine" | inn "nine" | nëntë "nine" < *newn̥-ti- | AB ñu | Lyc nuñtãta "nine" |
| *déḱm̥t "ten" | ten (< OE tien) | taíhun "ten" | decem "ten" | déka "ten" | dáśa "ten" | Av dasa, NPers dah- "ten" | OCS desętĭ "ten" | Lith dẽšimt, OPrus desimtan "ten" | Gaul decam- "ten"; Celtib tekam- "ten"; OIr deich, W deg, deng "ten" | tasn "ten" | dhjetë "ten" < *dék̂m̥t-i- | A śäk, B śak "ten" | |
| *wídḱm̥ti(h₁) "twenty" < *dwi-dḱm̥t-i(h₁) "two tens" | (remodelled) | (remodelled) | vīgintī "twenty" | eíkosi "twenty" | viṁśatí "twenty", dviṁśatí "twenty" | Av vīsaiti, Ossetian insäi "twenty" | (remodelled) | Lith dvidešimt "twenty" | OIr fiche (fichet), OW uceint "twenty" | kʿsan "twenty" | zet "twenty" | A wiki, B ikäṃ "twenty" | |
| *ḱm̥tóm "hundred" < *dḱm̥tóm | hundred (< OE hund, hund-red) | hunda (pl.) "hundred" | centum "hundred" | he-katón "hundred" | śatám "hundred" | Av satǝm "hundred" | OCS sŭto "hundred" | Lith šim̃tas, OPrus simtan "hundred" | OIr cét, W can(t) "hundred" | | qind "hundred" (possibly borrowed from Latin centum) | A känt, B kante "hundred" | |

### Gender of numerals

The numbers three and four had feminine forms with the suffix *-s(o)r-, reconstructed as *t(r)i-sr- and *kʷetwr̥-sr-, respectively.

## Numerals as prefixes

Special forms of the numerals were used as prefixes, usually to form bahuvrihis (like five-fingered in English):
| Number | Prefix (Fortson) |
| one- (together, same) | *sm̥- |
| two- | *dwi- |
| three- | *tri- |
| four- | *kʷ(e)tru- or *kʷetwr̥- |

## Ordinal numbers

The ordinal numbers are difficult to reconstruct due to their significant variation in the daughter languages. The following reconstructions are tentative:
* "first" is formed with *pr̥h₃- (related to some adverbs meaning "forth, forward, front" and to the particle *prō "forth", thus originally meaning "foremost" or similar) plus various suffixes like *-mo-, *-wo- (cf. Latin primus, Russian perv-).
* "second": The daughter languages use a wide range of expressions, often unrelated to the word for "two" (including Latin and English), so that no PIE form can be reconstructed. A number of languages use the form derived from *h₂enteros meaning "the other [of two]" (cf. OCS vĭtorŭ, Lithuanian añtras, Old Icelandic annarr, modern Icelandic annar).
* "third" to "sixth" were formed from the cardinals plus the suffix *-t(ó)-: *tr̥-t(ó)- / *tri-t(ó)- "third" etc.
* "seventh" to "tenth" were formed by adding the thematic vowel *-ó- to the cardinal: *oḱtow-ó- "eighth" etc.
The cardinals ending in a syllabic nasal (seven, nine, ten) inserted a second nasal before the thematic vowel, resulting in the suffixes *-mó- and *-nó-. These and the suffix *-t(ó)- spread to neighbouring ordinals, seen for example in Vedic aṣṭamá- "eighth" and Lithuanian deviñtas "ninth".

## Reflexes

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

### Reflexes of the cardinal numbers

| Number | Reconstruction (Sihler) | Reflexes |
| one | *Hoi-no- | Alb. njã > një (dialectal nji/njo), Lith. vienas, Latv. viens, Gaul. oinos, Gm. ein/eins, Eng. ān/one, Gk. οἶος oîos, Av. aēuua, Ir. óin/aon, Kashmiri akh, Lat. ūnus, Roman. unu, Osc. uinus, OCS edinŭ, ON einn, OPruss. aīns, Osset. iu/ieu, Pers. aiva-/yek, Kamviri ev, Pol. jeden, Russ. odin, Ved. aika, Umbr. uns, Goth. ains, Welsh un, Kurdish (Kurmanji) yek/êk |
| one | *sem- | Arm. mi/mek/meg, Alb. gjithë, Lith. sa, sav-as, Eng. sum/some, Gm. saman/zusammen, Gk. εἷς heîs, Hitt. san, Av. hakeret, Ir. samail/samhail, Lat. semel, Lyc. sñta, Kamviri sâ~, Pers. hama/hamin, Russ. odin, yedin, perviy Ved. sakŕ̥t, Toch. sas/ṣe, Welsh hafal, ON sami, Goth. sama |
| two | *du(w)o- | Hitt. dā-, Luv. tuwa/i-, Lyc. kbi-, Mil. tba-, Ved. dvā(u), Av. duua, Pers. duva/do, Osset. dyuuæ/duuæ, Kashmiri zū', Kamviri dü, Gk. δύο dúo, Lat. duō, Osc. dus, Umbr. tuf, Roman. doi, ON tveir, Goth. twai, Eng. twā/two, Gm. zwêne/zwei, Gaul. vo, Ir. dá/dó, Welsh dau, Arm. erkow/yerku/yergu, Toch. wu/wi, OPruss. dwāi, Latv. divi, Lith. dù, OCS dŭva, Pol. dwa, Russ. dva, Alb. dy;di/dy;dў, Kurdish (Kurmanji) du |
| three | *trei- | Hitt. teriyaš (gen. pl.), Lyc. trei, Ved. tráyas, Av. θrāiiō, Pers. çi/se, Osset. ærtæ/ærtæ, Kashmiri tre, Kamviri tre, Gk. τρεῖς treîs, Lat. trēs, Osc. trís, Umbr. trif, Roman. trei, ON þrír, Goth. þreis, Eng. þrēo/three, Gm. drī/drei, Gaul. treis, Ir. treí/trí, Welsh tri, Arm. erek῾/yerek῾/yerek῾, Toch. tre/trai, OPruss. tri, Latv. trīs, Lith. trỹs, OCS trije, Pol. trzy, Russ. tri, Alb. tre/tre. Kurdish (Kurmanji) sê |
| four | *kʷetwor- | Lyc. teteri, Ved. catvāras, Av. caθuuārō, Pers. /čahār, Osset. cyppar/cuppar, Kashmiri tsor, Kamviri što, Gk. τέτταρες téttares, Lat. quattuor, Osc. petora, Roman. patru, Umbr. petor, ON fjórir, Goth. fidwor, Eng. fēower/four, Gm. feor/vier, Gaul. petor, Ir. cethir/ceathair, Welsh pedwar, Arm. čork῾/čors/čors, Toch. śtwar/śtwer, OPruss. keturjāi, Latv. četri, Lith. keturì, OCS četyre, Pol. cztery, Russ. četyre, Alb. katër;katrë/katër, Kurdish (Kurmanji) çar |
| five | *pénkʷe | Luv. pa$^n$ta, Ved. pañca, Av. panca, Pers. panča/panj, Osset. fondz/fondz, Kashmiri pā.~tsh Kamviri puč, Gk. πέντε pénte, Lat. quīnque, Roman. cinci, Osc. pompe, Umbr. pumpe, ON fimm, Goth. fimf, Eng. fīf/five, Gm. fimf/fünf, Gaul. pempe, Ir. cóic/cúig, Welsh pump, Arm. hing/hing/hink, Toch. päñ/piś, OPruss. pēnkjāi, Latv. pieci, Lith. penkì, OCS pętĭ, Pol. pięć, Russ. pjat', Alb. pesë/pes(ë);pês, Kurdish (Kurmanji) pênc |
| six | *s(w)eḱs | Ved. ṣáṣ, Av. xšuuaš, Pers. /šeš, Osset. æxsæz/æxsæz, Kashmiri śe, Kamviri ṣu, Gk. ἕξ héx, Lat. sex, Osc. sehs, Umbr. sehs, ON sex, Goth. saíhs, Eng. siex/six, Gm. sëhs/sechs, Gaul. suex, Ir. sé/sé, Welsh chwech, Arm. vec῾/vec῾/vec῾, Toch. ṣäk/ṣkas, OPruss. usjai, Latv. seši, Lith. šešì, OCS šestĭ, Pol. sześć, Roman. șase, Russ. šest', Alb. gjashtë/gjasht(ë);xhasht, Kurdish (Kurmanji) şeş |
| seven | *septm̥ | Hitt. šipta-, Ved. saptá, Av. hapta, Pers. hafta/haft, Osset. avd/avd, Kashmiri sath, Kamviri sut, Gk. ἑπτά heptá, Lat. septem, Osc. seften, Roman. șapte, ON sjau, Goth. sibun, Eng. seofon/seven, Gm. sibun/sieben, Gaul. sextan, Ir. secht/seacht, Welsh saith, Arm. ewt῾n/yot῾/yot῾ě, Toch. ṣpät/ṣukt, OPruss. septīnjai, Lith. septynì, Latv. septiņi, OCS sedmĭ, Pol. siedem, Russ. sem', Alb. shtatë/shtat(ë), Kurdish (Kurmanji) heft |
| eight | *h₃eḱtō | Lyc. aitãta-, Ved. aṣṭā(u), Av. ašta, Pers. ašta/hašt, Osset. ast/ast, Kashmiri ā.ṭh, Kamviri uṣṭ, Gk. ὀκτώ oktṓ, Lat. octō, Roman. opt, Osc. uhto, ON átta, Goth. ahtau, Eng. eahta/eight, Gm. ahto/acht, Gaul. oxtū, Ir. ocht/ocht, Welsh wyth, Arm. owt῾/ut῾ě, Toch. okät/okt, OPruss. astōnjai, Latv. astoņi, Lith. aštuonì, OCS osmĭ, Pol. osiem, Russ. vosem', Alb. tëte/tet(ë), Kurdish (Kurmanji) heşt |
| nine | *(h₁)newn̥ | Lyc. ñuñtãta-, Ved. nava, Av. nauua, Pers. nava/noh, Kashmiri nav, Kamviri nu, Gk. ἐννέ(ϝ)α enné(w)a, Lat. novem, Osc. nuven, Umbr. nuvim, Roman. nouă, ON níu, Goth. niun, Eng. nigon/nine, Gm. niun/neun, Gaul. navan, Ir. nói/naoi, Welsh naw, Arm. inn/inn/inně, TochA. ñu, OPruss. newīnjai, Latv. deviņi, Lith. devynì, OCS devętĭ, Pol. dziewięć, Russ. devjat', Alb. nëntë/nëndë/nând(ë);non(t), Kurdish (Kurmanji) neh, no |
| ten | *deḱm̥(t) | Ved. dáśa, Av. dasa, Pers. daθa/dah, Osset. dæs/dæs, Kashmiri da.h, Kamviri duc, Gk. δέκα déka, Lat. decem, Osc. deken, Umbr. desem, Roman. zece, ON tíu, Goth. taíhun, Eng. tīen/ten, Gm. zëhen/zehn, Gaul. decam, Ir. deich/deich, Welsh deg, Arm. tasn/tas/dasě, Toch. śäk/śak, OPruss. desīmtan, Latv. desmit, Lith. dẽšimt, OCS desętĭ, Pol. dziesięć, Russ. desjat', Alb. dhjetë/dhet(ë), Kurdish (Kurmanji) deh, de |
| twenty | *wīḱm̥t- | Ved. viṁśatí-, Av. vīsaiti, Pers. /bēst, Kashmiri vuh, Kamviri vici, Doric ϝίκατι wíkati, Lat. vīgintī, Gaul. vocontio, Ir. fiche/fiche, M. Welsh ugein(t), Arm. k῾san/k῾san/k῾san, Toch. wiki/ikäṃ, Lith. dvi-de-šimt, Alb. njëzet/njizet, Kurdish (Kurmanji) bîst |
| thirty | *trīḱomt- | Skr. triṅśat, Gk. τριάκοντα triákonta, Lat. trīgintā, Ir. trícho/tríocha, Lith. tris-de-šimt, Kurdish (Kurmanji) sih, sî |
| forty | *kʷetwr̥̄ḱomt- | Skr. catvāriṅśat, Gk. τεσσαράκοντα tessarákonta, Lat. quadrāgintā, Ir. cethorcho/ceathracha, Lith. keturias-de-šimt, Kurdish (Kurmanji) çil |
| fifty | *penkʷēḱomt- | Skr. pañcāśat, Gk. πεντήκοντα pentḗkonta, Lat. quinquāgintā, Ir. coíca/caoga, Lith. penkias-de-šimt, Kurdish (Kurmanji) pênceh, pêncî |
| sixty | *s(w)eḱsḱomt- | Skr. ṣaṣṭih, Gk. ἑξήκοντα hexḗkonta, Lat. sexāgintā, Ir. sesca/seasca, Lith. šešias-de-šimt, Russ. šest'desjat, Kurdish (Kurmanji) şêst |
| seventy | *septm̥̄ḱomt- | Skr. saptatih, Gk. ἑβδομήκοντα hebdomḗkonta, Lat. septuāgintā, Ir. sechtmoga/seachtó, Lith. septynias-de-šimt, Russ. sem'desjat, Kurdish (Kurmanji) heftê |
| eighty | *h₃eḱtō(u)ḱomt- | Skr. aśītih, Gk. ὀγδοήκοντα ogdoḗkonta, Lat. octōgintā, Ir. ochtmoga/ochtó, Lith. aštuonias-de-šimt, Russ. vosem'desjat, Kurdish (Kurmanji) heştê |
| ninety | *(h₁)newn̥̄ḱomt- | Skr. navatih, Gk. ἐνενήκοντα enenḗkonta, Lat. nōnāgintā, Ir. nócha/nócha, Lith. devynias-de-šimt, Russ. devjanosto, Kurdish (Kurmanji) not, newet |
| hundred | *ḱm̥tom | Ved. śatám, Av. satəm, Roman. sută, Pers. /sad, Osset. sædæ, Kashmiri śath, Gk. ἑκατόν hekatón, Lat. centum, ON hundrað, Goth. hund, Eng. hundred/hundred, Gm. hunt/hundert, Gaul. cantam, Ir. cét/céad, Welsh cant, Toch. känt/kante, Latv. simts, Lith. šim̃tas, OCS sŭto, Pol. sto, Russ. sto/sotnja, Kurdish (Kurmanji) sed |
| thousand | *(sm̥-)ǵʰéslo- | Skr. sahasram, Av. hazarəm, Pers. /hazār, Gk. χίλιοι khílioi, Lat. mīlle, Kurdish (Kurmanji) hezar |
| thousand | *tusdḱomti | ON þúsund, Goth. þūsundi, Eng. þūsend/thousand, Gm. þūsunt/tausend, TochA. tmāṃ, TochB. tmāne/tumane, Lith. tūkstantis, Latv. tūkstots, OCS tysǫšti, Pol. tysiąc, Russ. tys'ača |
| thousand | *wel-tyo- | Toch. wälts/yaltse; OCS velьjь/velikъ |
In the following languages, reflexes separated by slashes mean:
* Albanian: Tosk Albanian / Gheg Albanian
* Armenian: Classical Armenian / Eastern Armenian / Western Armenian
* English: Old English / Modern English
* German: Old High German / New High German
* Irish: Old Irish / Modern Irish
* Ossetic: Iron / Digor
* Persian: Old Persian / Modern Persian
* Tocharian: Tocharian A / Tocharian B

### Reflexes of the feminine numbers

| Number | Reconstruction | Reflexes |
| three | *t(r)i-sr- | Ved. tisrás, Av. tišrō, Gaul. tidres, Ir. teoir/? |
| four | *kʷetwr̥-sr- | Ved. cátasras, Av. cataŋrō, Lith. keturios, Ir. cetheoir/? |

### Reflexes of the numeral prefixes

| Number | Reconstruction | Reflexes (with examples) |
| one- (together, same) | *sm̥- | Ved. sa-kŕ̥t "once", Gk. ᾰ̔πλόος haplóos "one-fold, simple", Lat. sim-plex "one-fold" |
| two- | *dwi- | Ved. dvi-pád- "two-footed", Gk. dí-pod- "two-footed", Archaic Lat. dui-dent "a sacrificial animal with two teeth", Lith. dvi-kojis "two-footed" |
| three- | *tri- | Ved. tri-pád- "three-footed", Gk. trí-pod- "three-footed (table)", Lat. tri-ped- "three-footed", Lith. tri-kojis "three-footed", Gaul. tri-garanus "having three cranes", Alb. tri-dhjetë "thirty" (three ten) |
| four- | *kʷ(e)tru- | Ved. cátuṣ-pád- "four-footed", Av. caθru-gaoša- "four-eared", Gk. tetrá-pod- "four-footed", Lat. quadru-ped- "four-footed", Lith. ketur-kojis "four-footed" |

### Reflexes of the ordinal numbers

| Number | Reconstruction | Reflexes |
| first | *pr̥h₃-wó- | Ved. pūrviyá-, Lat. prīvus, OCS prĭvŭ, Pol. pierwszy, Russ. pervyj, Toch. parwät/parwe |
| first | *pr̥h₃-mó- | Goth. fruma, Lith. pìrmas, Latv. pirmais, Lat. prīmus, Osc. perum |
| first | other forms | Eng. fyrst/first, Hitt. para, Lyc. pri, Av. pairi, vienet-as, paoiriia, Osset. fyccag, farast/farast, Kamviri pürük, Gk. πρῶτος prôtos, Umbr. pert, ON fyrstr, Gm. furist/Fürst "prince, ruler"; fruo/früh "early", Ir. er/air, Welsh ar, OPruss. pariy, Alb. i parë |
| second | *(d)wi-teró- | Skr. dvitīya, Gk. δεύτερος deúteros, Russ. vtoroj |
| third | *tri-t(y)ó- | Ved. tr̥tīya-, Gk. τρίτος trítos, Lat. tertius, Alb. (i) tretë, Lith. trečias < *tretias, Russ. tretij |
| fourth | *kʷetwr̥-tó- | Gk. τέταρτος tétartos, Eng. feorþa/fourth, OCS četvrĭtŭ, Alb. (i) katërt, Lat. quārtus, Lith. ketvirtas, Russ. chetv'ortyj |
| fifth | *penkʷ-tó- | Av. puxδa-, Gk. πέμπτος pémptos, Lat. quīntus, Alb. (i) pestë, Lith. penktas, Russ. p'atyj |
| sixth | *sweḱs-tó- | Gk. ἕκτος héktos, Lat. sextus, Alb.(i) gjashtë, Lith. šeštas, Russ. šestoj |
| seventh | *septm̥-(m/t)ó- | Gk. ἕβδομος hébdomos, Lat. septimus, OCS sedmŭ, Lith. sẽkmas (then displaced by the neologism "septintas") Russ. sed'moj |
| eighth | *h₃eḱtōw-ó-s | Gk. ὄγδο(ϝ)ος ógdo(w)os, Lat. octāvus, Russ. vos'moj |
| eighth | *oḱtm-o-s? | Lith. ašmas (then displaced by the neologism "aštuntas") |
| ninth | *(h₁)newn̥-(n/t)ó- | Lat. nōnus, Gk. ἔνατος énatos, Pruss. newīnts; Russ. dev'atyj |
| tenth | *deḱm̥-(m/t)ó- | Ved. daśamá-, Av. dasəma-, Lat. decimus, Gk. δέκατος dékatos, Lith. dešimtas, Russ. desjatyj |