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)[1]	Reconstruction (Beekes)[2]
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"[citation needed])	*ǵʰesl-

Other reconstructions typically differ only slightly from Beekes and Sihler. A nineteenth-century reconstruction (by Brugmann) for thousand is *tūsḱmtiə.^[3][4] See also Fortson 2004.^[5]

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^[6] 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."

This table is transcluded from Indo-European vocabulary. (edit | history)

See also: Proto-Indo-European numerals

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)")[7]	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-[a]	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"[b][9]
*tréyes (fem. *tisres,[10] 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"[c]	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"[d]	Gaul petuar[ios] "four"[12] 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"[e]	pénte "five"	páñca "five"; Mitanni-Aryan panza- "five"[7]	Av panča "five"; Kurd pênc/pênz	OCS pętĭ "five"	Lith penkì, OPrus penkei "five"[f]	Gaul pinpe-, pompe "five"[12] 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";[12] 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"[7]	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"[g]	Lith aštuonì, OPrus astonei, Latg ostoni "eight"	Gaul oxtu- "eight"[12] OIr ocht n- "eight";[h] W wyth "eight"	utʿ "eight"	tetë "eight" < *H₁ok̂tō-t-	A okät, B okt "eight"	Lyc aitãta "eight"[15]
*(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"[16]
*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";[12] Celtib tekam- "ten";[17] OIr deich, W deg, deng "ten"	tasn "ten"	dhjetë "ten" < *dék̂m̥t-i-	A śäk, B śak "ten"	[i]
*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.^[5]

Numerals as prefixes

Special forms of the numerals were used as prefixes, usually to form bahuvrihis (like five-fingered in English):

Number	Prefix (Fortson)[19]
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:^[20]

• "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[5][21]
one	*Hoi-no-[22]	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
	*sem-[23]	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-[24]	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-[25]	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-[26]	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[27]	Luv. panta, 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[28]	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[29]	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[30]	Lyc. aitãta-,[31] 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[32]	Lyc. ñuñtãta-,[33] 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)[34]	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[citation needed], Kurdish (Kurmanji) sih, sî
forty	*kʷetwr̥̄ḱomt-	Skr. catvāriṅśat, Gk. τεσσαράκοντα tessarákonta, Lat. quadrāgintā, Ir. cethorcho/ceathracha, Lith. keturias-de-šimt[citation needed], Kurdish (Kurmanji) çil
fifty	*penkʷēḱomt-	Skr. pañcāśat, Gk. πεντήκοντα pentḗkonta, Lat. quinquāgintā, Ir. coíca/caoga, Lith. penkias-de-šimt[citation needed], 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[citation needed], Kurdish (Kurmanji) şêst
seventy	*septm̥̄ḱomt-	Skr. saptatih, Gk. ἑβδομήκοντα hebdomḗkonta, Lat. septuāgintā, Ir. sechtmoga/seachtó, Lith. septynias-de-šimt, Russ. sem'desjat[citation needed], Kurdish (Kurmanji) heftê
eighty	*h₃eḱtō(u)ḱomt-	Skr. aśītih, Gk. ὀγδοήκοντα ogdoḗkonta, Lat. octōgintā, Ir. ochtmoga/ochtó, Lith. aštuonias-de-šimt, Russ. vosem'desjat[citation needed], Kurdish (Kurmanji) heştê
ninety	*(h₁)newn̥̄ḱomt-	Skr. navatih, Gk. ἐνενήκοντα enenḗkonta, Lat. nōnāgintā, Ir. nócha/nócha, Lith. devynias-de-šimt, Russ. devjanosto[citation needed], Kurdish (Kurmanji) not, newet
hundred	*ḱm̥tom[35]	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
	*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
	*wel-tyo-[36]	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[5]
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)[19][37]
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,[20] Pol. pierwszy, Russ. pervyj, Toch. parwät/parwe
	*pr̥h₃-mó-	Goth. fruma, Lith. pìrmas,[20] Latv. pirmais, Lat. prīmus, Osc. perum
	other forms	Eng. fyrst/first,[20] 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[citation needed]
third	*tri-t(y)ó-	Ved. tr̥tīya-, Gk. τρίτος trítos, Lat. tertius,[20] Alb. (i) tretë, Lith. trečias < *tretias, Russ. tretij[citation needed]
fourth	*kʷetwr̥-tó-	Gk. τέταρτος tétartos, Eng. feorþa/fourth, OCS četvrĭtŭ,[20] Alb. (i) katërt, Lat. quārtus, Lith. ketvirtas, Russ. chetv'ortyj[citation needed]
fifth	*penkʷ-tó-	Av. puxδa-, Gk. πέμπτος pémptos,[20] Lat. quīntus, Alb. (i) pestë, Lith. penktas, Russ. p'atyj[citation needed]
sixth	*sweḱs-tó-	Gk. ἕκτος héktos, Lat. sextus,[20] Alb.(i) gjashtë, Lith. šeštas, Russ. šestoj[citation needed]
seventh	*septm̥-(m/t)ó-	Gk. ἕβδομος hébdomos, Lat. septimus, OCS sedmŭ,[20] Lith. sẽkmas (then displaced by the neologism "septintas") Russ. sed'moj[citation needed]
eighth	*h₃eḱtōw-ó-s	Gk. ὄγδο(ϝ)ος ógdo(w)os, Lat. octāvus,[20] Russ. vos'moj
	*oḱtm-o-s?	Lith. ašmas (then displaced by the neologism "aštuntas")
ninth	*(h₁)newn̥-(n/t)ó-	Lat. nōnus,[20] Gk. ἔνατος énatos, Pruss. newīnts; Russ. dev'atyj
tenth	*deḱm̥-(m/t)ó-	Ved. daśamá-, Av. dasəma-, Lat. decimus,[20] Gk. δέκατος dékatos, Lith. dešimtas, Russ. desjatyj[citation needed]

Notes

1. All suggested etymologies of një "one" are highly speculative, at best. This etymology is one of two given by E. Hamp in Indo-European Numerals (Jadranka Gvozdanović, ed., 1992), pp. 903-904; the other is simply from PIE *eni- (or H₂en-), a PIE deictic particle visible in Sanskrit anyá- "the other", OCS onŭ "that one", Lithuanian anàs "that one". Michiel de Vaan, in a review of Demiraj's Sistemi i numerimit, suggests PIE *H₂en-io-no- > pre-Proto-Albanian *ëńán > Proto-Albanian *ńâ > një. M. Huld (Basic Albanian Etymologies, p. 101) attempts to derive një from PIE *sm-iH₂, feminine of *sem "one" and reflected in Ancient Greek mía; this etymology is also tentatively suggested in Don Ringe et al. "IE and Computational Cladistics", p. 75 (Transactions of the Philological Society 100, 2002).
2. For example, qñnã-tba "twelve" (litt. "ten" plus "two").^[8]
3. See also: Umb peturpursus "quadruped".
4. Cf. Thr ketri- "four".^[11]
5. See also: Osc pomp- "five".^[13]
6. See also Phry pinke "five".^[14]
7. Built upon osmŭ "eighth" < *H₁ok̂t-mo-.
8. With nasalization after *septḿ̥ "seven".
9. There is the possibility that Lycian sñta could mean either "ten" or "(one) hundred".^[15][18]