Indo-European copula

A feature common to all Indo-European languages is the presence of a verb corresponding to the English verb to be. Though in some languages it is vestigial, it is present nonetheless in atrophied forms or derivatives.

General features

This verb has two basic meanings. In a less marked context it is a simple copula (I'm tired; That's a shame!), a function which in non-Indo-European languages can be expressed quite differently. In a more heavily marked context it expresses existence (I think therefore I am); the dividing line between these is not always easy to draw. In addition, many Indo-European languages use this verb as an auxiliary for the formation of compound (periphrastic) tenses (I'm working; I was bitten). Other functions vary from language to language. For example, although in its basic meanings, to be is a stative verb, English puts it to work as a dynamic verb in fixed collocations (You are being very annoying).

The copula is the most irregular verb in many Indo-European languages. This is partly because it is more frequently used than any other, and partly because Proto-Indo-European offered more than one verb suitable for use in these functions, with the result that the daughter languages, in different ways, have tended to form suppletive verb paradigms. This article describes the way in which the irregular forms have developed from a series of roots.

The Proto-Indo-European roots

*h₁es-

Look up Appendix:Proto-Indo-European/h₁és- in Wiktionary, the free dictionary.

The root *h₁es- was certainly already a copula in Proto-Indo-European. The e-grade (see Indo-European ablaut) is found in such forms as English is, Irish is, German ist, Latin est, Sanskrit asti, while the zero grade produces forms beginning with /s/, like German sind, Latin sumus, Vedic Sanskrit smas, etc. In PIE, *h₁es- was an athematic verb in -mi; that is, the first person singular was *h₁esmi; this inflection survives in English am, Persian am, Sanskrit asmi, Old Church Slavonic есмь (esmĭ), etc.

This verb is generally reconstructed for Proto-Indo-European thus:^[1]

Person	Present indicative	Imperfect indicative	Subjunctive	Optative	Imperative
1st singular	*h1és-mi	*h1és-m̥	*h1és-oh2	*h1s-iéh1-m	—
2nd singular	*h1és-i	*h1és	*h1és-esi	*h1s-iéh1-s	*h1és, *h1s-dʰí
3rd singular	*h1és-ti	*h1és-t	*h1és-eti	*h1s-iéh1-t	*h1és-tu
1st dual	*h1s-uós	*h1s-ué	*h1és-owos	*h1s-ih1-wé	—
2nd dual	*h1s-tés	*h1s-tóm	*h1és-etes	*h1s-ih1-tóm	*h1s-tóm
3rd dual	*h1s-tés	*h1s-tā́m	*h1és-etes	*h1s-ih1-tā́m	*h1s-tā́m
1st plural	*h1s-m̥ós	*h1s-m̥é	*h1és-omos	*h1s-ih1-mé	—
2nd plural	*h1s-té	*h1s-té	*h1és-ete	*h1s-ih1-té	*h1s-té
3rd plural	*h1s-énti	*h1s-énd	*h1és-onti	*h1s-ih1-énd	*h1s-éntu

*bʰuH-

The root *bʰuH- or *bʰuh₂- (which did not have ablaut variations in the protolanguage^[2]) probably meant 'to grow', but also 'to become'. This is the source of the English infinitive be and participle been (Germanic participles have the suffix in -an). Also, for example, the Scottish Gaelic "future" tense bithidh; the Irish imperative bí, past bhí and future beidh; and the Slavic infinitive, etc. for example Russian быть (byt’). PIE *b^h becomes Latin /f/, hence the Latin future participle futūrus and perfect fuī; Latin fīō 'I become' is also from this root, as is the Greek verb φύω (phúō), from which physics and physical are derived.

This verb can be reconstructed as follows:^[1]

Person	Indicative	Subjunctive	Optative	Imperative
1st singular	*bʰúH-m	*bʰúH-oh2	*bʰuH-yéh1-m	—
2nd singular	*bʰúH-s	*bʰúH-esi	*bʰuH-yéh1-s	*bʰúH, *bʰuH-dʰí
3rd singular	*bʰúH-t	*bʰúH-eti	*bʰuH-yéh1-t	*bʰúH-tu
1st dual	*bʰuH-wé	*bʰúH-owos	*bʰuH-ih1-wé	—
2nd dual	*bʰuH-tóm	*bʰúH-etes	*bʰuH-ih1-tóm	*bʰuH-tóm
3rd dual	*bʰuH-tā́m	*bʰúH-etes	*bʰuH-ih1-tā́m	*bʰuH-tā́m
1st plural	*bʰuH-mé	*bʰúH-omos	*bʰuH-ih1-mé	—
2nd plural	*bʰuH-té	*bʰúH-ete	*bʰuH-ih1-té	*bʰuH-té
3rd plural	*bʰuH-énd	*bʰúH-onti	*bʰuH-ih1-énd	*bʰuH-éntu

*wes-

The root *wes- may originally have meant "to live". The e-grade is present in the German participle gewesen, the o-grade (*wos-) survives in English and Old High German was, while the lengthened e-grade (*wēs-) gives us English were. (The Germanic forms with /r/ result from grammatischer Wechsel.) See Germanic strong verb: Class 5.

*h₁er-

This has been claimed as the origin of the Old Norse and later Scandinavian languages' present stem: Old Norse em, ert, er, erum, eruð, eru; the second person forms of which were borrowed into English as art and are.^[3]

However, other authorities link these forms with *h₁es- and assume grammatischer Wechsel (/s/→/r/), although this is not normally found in the present stem. Donald Ringe argues that the copula was sometimes unaccented in Pre-Proto-Germanic, which would have then triggered the voicing under Verner's law.^[1] He explains the Germanic first person singular form *immi as such, deriving it from earlier *ezmi, since -zm-, but not -sm-, was assimilated to -mm- in Germanic (for which other evidence exists as well). Furthermore, the third person plural form *sindi (from PIE *h₁sénti) shows that this word, too, was unaccented. If the accent had been preserved, it would have become *sinþi, but that form is not found in any Germanic language. In this view, it is likely that stressed and unstressed varieties of the copula (with corresponding voiceless and voiced fricatives) existed side by side in Germanic, and the involvement of a separate root *h₁er- is unnecessary.

*steh₂-

The root *(s)teh₂- meant "to stand". From this root comes the present stem of the so-called "substantive verb" in Irish and Scottish Gaelic, tá and tha respectively. On the absence of the initial s- in Celtic, see Indo-European s-mobile. In Latin, stō, stare retained the meaning "to stand", until local forms of Vulgar Latin began to use it as a copula in certain circumstances. Today, this survives in that several Romance languages use it as one of their two copulae, and there is also a Romance tendency for a past participle derived from *steh₂- to replace that of the main copula. See also Romance copula.

The resulting paradigms

Hittite

The Hittite verb "to be" is derived from the Indo-European root *h₁es-.

	Present indicative	Preterite indicative	Imperative
1st sg.	ēšmi	ešun	ēšlit ēšlut ašallu
2nd sg.	ēšši	ēšta	ēš
3rd sg.	ēšzi	ēšta	ēšdu
1st pl.	(ašweni)	ēšwen	–
2nd pl.	ēšteni	ēšten	ēšten
3rd pl.	ašanzi	ešer	ašandu

Indo-Iranian languages

Vedic Sanskrit

The Vedic Sanskrit verb as (to be) is derived from the Indo-European root *h₁es-.

Person	Present, Indicative, Active
	Singular	Dual	Plural
1st	asmi	svas	smas
2nd	asi	sthas	stha
3rd	asti	stas	santi

bhū (to be) is derived from Indo-European *b^huH-.

Person	Present, Indicative, Active
	Singular	Dual	Plural
1st	bhavāmi	bhavāvas(i)	bhavāmas(i)
2nd	bhavasi	bhavathas	bhavatha
3rd	bhavati	bhavatas	bhavanti

Persian

Persian grammar differentiates the marked or substantive verb هستن hastan from the unmarked enclitic copula است ast.^[4] Hastan is used to express existence while ast in the present tense expresses predication, although hastan can also be used for emphasis to express predication in the present tense. In the past tense, the verb بودن budan covers both meanings.

Strictly speaking, hastan is only a theoretical infinitive, not lexical: budan functions as the actual infinitive of hast, used, for example, in present-tense modal constructions like شايد بود shāyad bud 'it may be'. The present stem of budan is باش bāsh-, used for the imperative and subjunctive, e.g. چنين باشد chonin bāshad 'may it be so!'.

The verb hast (to be) is derived from the Indo-European root *h₁es-, where bud (to be) is derived from Indo-European *b^huH-.

	Substantive verb	Enclitic copula
Present	هستم hastam هستى hasti هست hast هستيم hastim هستيد hastid هستند hastand	م -am ى -i است ast يم -im يد -id ند -and
Preterite	بودم budam بودى budi بود bud بوديم budim بوديد budid بودند budand

Greek

The Ancient Greek verb eimi (I am) is derived from the Indo-European root *h₁es-.

		Homeric Greek	Classical Attic	Modern Greek
Present indicative	1st sg. 2nd sg. 3rd sg. 1st pl. 2nd pl. 3rd pl.	εἰμί (eimi) εἶς, ἐσσί (eis, essi) ἐστί(ν) (esti(n)) εἰμέν (eimen) ἐστέ (este) εἰσί(ν), ἔασι (eisi(n), easi)	εἰμί (eimi) εἶ (ei) ἐστί(ν) (esti(n)) ἐσμέν (esmen) ἐστέ (este) εἰσί(ν) (eisi(n))	είμαι (ime) είσαι (ise) είναι (ine) είμαστε (imaste) είστε (iste) είναι (ine)
Preterite indicative	1st sg. 2nd sg. 3rd sg. 1st pl. 2nd pl. 3rd pl.	ἦα, ἔον (ēa, eon) ἦσθα, ἔησθα (ēstha, eēstha) ἦ(ε)ν, ἔην (ē(e)n, eēn) ἦμεν (ēmen) ἦτε (ēte) ἦσαν (ēsan)	ἦ(ν) (ē(n)) ἦς, ἦσθα (ēs, ēstha) ἦν (ēn) ἦμεν (ēmen) ἦστε, ἔατε (ēste, eate) ἦσαν ἔσαν (ēsan, esan)	ήμουν (imun) ήσουν (isun) ήταν (itan) ήμασταν (imastan) ήσασταν (isastan) ήταν (itan)
Subjunctive	1st sg. 2nd sg. 3rd sg. 1st pl. 2nd pl. 3rd pl.	ἔω (eō) ἔῃς, ἔοις (eēis, eois) ἔῃ(σι), ᾖσι(ν), ἔοι (eēi(si), ēisi(n), eoi)     ἔωσι(ν) (eōsi(n))	ὦ (ō) ᾖς (ēis) ᾖ (ēi) ὦμεν (ōmen) ἦτε (ēte) ὦσι(ν) (ōsi(n))
Optative	1st sg. 2nd sg. 3rd sg. 1st pl. 2nd pl. 3rd pl.	εἴην (eiēn) εἴης (eiēs) εἴη (eiē)   εἶτε (eite) εἶεν (eien)	εἴην (eiēn) εἴης (eiēs) εἴη (eiē) εἴημεν, εἶμεν (ei(ē)men) εἴητε, εἶτε (ei(ē)te) εἴησαν, εἶεν (eiēsan, eien)
Imperative	2nd sg. 2nd pl.	ἔσσο, ἴσθι (esso, isthi) ἔστε (este)
Infinitive		εἶναι, ἔμ(μ)εν(αι) (einai, em(m)en(ai))	εἶναι (einai)
Participle		ἐών, ἐόντ- (eōn, eont-) fem. ἐοῦσα (eousa)	ὦν, ὄντ- (ōn, ont-) fem. οὖσα (ousa)

Italic languages

Except for Latin, the older Italic languages are very scarcely attested, but we have in Oscan set (they are), fiiet (they become), fufans (they have been) and fust (he will be), and in Umbrian sent (they are). This section will explain Latin, and the Romance languages that have evolved from it.

In Spanish, Catalan, Galician-Portuguese and to a lesser extent, Italian there are two parallel paradigms, ser/èsser/essere from Latin esse "to be" on one hand, and estar/stare from Latin stare, "to stand" on the other.

For simplicity, the table below has only the full conjugation of the present tense, and the first-person singular forms of some other tenses.

	Latin		Old French		French	Spanish		Italian		Portuguese		Catalan		Romanian
Infinitive	esse	stāre	estre	ester	être	ser	estar	essere	stare	ser	estar	ser, ésser	estar	fi
Present indicative	sum es est sumus estis sunt	stō stās stat stāmus stātis stant	suis es est sommes estes sont	este estes este estons estez estent	suis es est sommes êtes sont	soy eres es somos sois son	estoy estás está estamos estáis están	sono sei è siamo siete sono	sto stai sta stiamo state stanno	sou és é somos sois são	estou estás está estamos estais estão	sóc ets és som sou són	estic estàs està estem esteu estan	sunt eşti este suntem sunteţi sunt
Present subjunctive	sim	stem	sois	este	sois	sea	esté	sia	stia	seja	esteja	sigui	estigui	fiu
Preterite	fuī	stetī	fus	estai	fus	fui	estuve	fui	stetti	fui	estive	fui	estiguí	fusei
Imperfect	eram	stābam	ier	estais	étais	era	estaba	ero	stavo	era	estava	era	estava	eram
Future	erō	stābō	serai	esterai	serai	seré	estaré	sarò	starò	serei	estarei	seré	estaré	voi fi
Past participle		statum		esté	été	sido	estado	stato	stato	sido	estado	estat / sigut (dialect)	estat	fost

In several modern Romance languages, the perfect is a compound tense formed with the participle as in English, but the old Latin perfect survives as a commonly used preterite in Spanish and Portuguese, and as a literary "past historic" in French, Italian and Catalan.

There is a tendency for a past participle derived from stare (or more specifically its supine, statum) to replace that of the main copula derived from esse. For example, the French participle été comes from statum.

For further information, see the main article.

Germanic languages

Proto-Germanic retained the dual, but only in the first and second person.

	Proto-Germanic (reconstructed)		Gothic	Old Norse	Icelandic	Faroese	Nynorsk Norwegian	Norwegian Bokmål + Danish		Old Swedish	Swedish	Old English		English	Old High German	German	Luxem- burgish	Old Saxon	Dutch
Infinitive	*wesaną	*beuną?	wisan	vera	vera	vera	vera/vere	være		vara	vara	wesan	bēon	be	wesan	sein	sinn	wesan	zijn / wezen
Present indicative	*immi *izi *isti *izū *izudiz *izum *izud *sindi	*biumi *biusi *biuþi *beū? *biuþiz *beum *beuþ *biunþi	im is ist siju sijuts sijum sijuþ sind	em ert (est) er (es) – – erum eruð eru	er ert er – – erum eruð eru	eri ert er – – eru eru eru	er er er – – er er er	er er er – – er er er		æm/ær æst ær – – ærum ærin æru	är är är – – är (äro) är (ären) är (äro)	eom eart is – – sint sint sint	bēo bist biþ – – bēoþ bēoþ bēoþ	am art is – – are are are	bim, bin bist ist – – birum, bir(e)n birut, bir(e)t sint	bin bist ist – – sind seid sind	si(nn) bass ass – – si(nn) sidd si(nn)	bium bist is – – sind sind sind	ben – is – – zijn zijn (zijt) zijn
Present subjunctive	*sijǭ *sijēs *sijē *sīw *sīþiz *sīm *sīþ *sīn	*biwjǭ? *biwjēs? *biwjē? *biwīw *biwīþiz *biwīm *biwīþ *biwīn	sijau sijais sijai sijaiwa sijaits sijaima sijaiþ sijaina	sjá sér sé – – sém séð sé	sé sért sé – – séum séuð séu	veri veri veri – – veri veri veri	– – (vere) – – – – –	– – (være) – – – – –		– – sē(i)/vari – – – – sēi(n)/vari(n)	– – (vare) – – – – –	sīe sīe sīe – – sīen sīen sīen	bēo bēo bēo – – bēon bēon bēon	be be be – – be be be	sī sīs(t) sī – – sīm, sīn sī(n)t sīn	sei sei(e)st sei – – seien seiet seien	– – sief – – – – –	sī sīs(t) sī – – sīn sīn sīn	zij – zij – – zijn zijn (zijt) zijn
Preterite indicative	*was *wast *was *wēzū *wēzudiz *wēzum *wēzud *wēzun		was wast was wēsu wēsuts wēsum wēsuþ wēsun	var varst var – – várum várið váru	var varst var – – vorum voruð voru	var vart var – – vóru vóru vóru	var var var – – var var var	var var var – – var var var		var vast var – – vārum vārin vāru	var var var – – var (voro) var (voren) var (voro)	wæs wǽre wæs – – wǣron wǣron wǣron		was wast was – – were were were	was wāri was – – wārum wārut wārun	war warst war – – waren wart waren	war waars war – – ware(n) waart ware(n)	was wāri was – – wārun wārun wārun	was – was – – waren waren (waart) waren
Preterite subjunctive	*wēzį̄ *wēzīz *wēzī *wēzīw *wēzīdiz *wēzīm *wēzīd *wēzīn		wēsjau wēseis wēsi wēseiwa wēseits wēseima wēseiþ wēseina	væra værir væri – – værim værið væri	væri værir væri – – værum væruð væru	væri væri væri – – væri væri væri	– – – – – – – –	var var var – – var var var		– – vāri – – – – vāri(n)	vore vore vore – – vore vore (-en) vore	wǣre wǣre wǣre – – wǣren wǣren wǣren		were wert were – – were were were	wāri wārīs wāri – – wārīm wārīt wārīn	wäre wärest wäre – – wären wäret wären	wier wiers wier – – wiere(n) wiert wiere(n)	wāri wāris wāri – – wārin wārin wārin	ware – ware – – waren waren (waart) waren
Past participle	–		–	verit	verið	verið	vore (vori)	vært	været	varin	varit	–		been	giwesan	gewesen	gewiescht	(gi)wesan	geweest

Old English kept the verbs wesan and bēon separate throughout the present stem, though it is not clear that they made the kind of consistent distinction in usage that we find, for example in Spanish. In the preterite, however, the paradigms fell together. Old English has no participle for this verb.

The plural forms in Modern Swedish (indicated in brackets) were in common use in formal written language until the mid-20th century, but are now no longer in use except in deliberately archaising texts. The preterite subjunctive is also increasingly being replaced by the indicative.

Dutch, like English, has abandoned the original second-person singular forms, replacing them with the second-person plural forms. However, while in English the old forms are still in limited and deliberately archaic use, in Dutch they have disappeared entirely and are no longer known or used at all.

Slavic languages

	Proto-Slavic (reconstructed)	Old Church Slavonic	Ukrainian	Russian	Polish	Czech	Slovak	Slovenian	Serbo-Croatian	Bulgarian
Infinitive	*byti	byti	бути, buty	быть, byt'	być	být	byť	biti	biti
Present	*(j)esmĭ *(j)esi *(j)estĭ *(j)esvě *(j)esta *(j)este *(j)esmŭ *(j)este *sǫtĭ	jesmĭ jesi jestŭ jesvě jesta jeste jesmŭ jeste sǫtŭ	єсмь, jesm' / емь, em' єси, jesy є, je / єсть, jest' – – – смо, smo сте, ste суть, sut'	есмь, jesm' еси, jesi есть, jest' – – – есмы, jesmy есте, jeste суть, sut'	jestem, -m jesteś, -ś jest – – – jesteśmy, -śmy jesteście, -ście są	jsem jsi je – – – jsme jste jsou	som si je – – – sme ste sú	sem si je sva sta sta smo ste so	jesam, sam/budem* jesi, si/budeš jest, je/bude – – – jesmo, smo/budemo jeste, ste/budete jesu, su/budu	съм, səm си, si е, e – – – сме, sme сте, ste са, sa
Imperative	– *bǫdi *bǫdi *bǫděvě *bǫděta – *bǫděmŭ *bǫděte *bǫdǫ	– bǫdi bǫdi bǫděvě bǫděta – bǫděmŭ bǫděte bǫdǫ	– будь, bud' будь, bud' – – – будьмо, budĭmo будьте, bud'te будуть, budut'	– будь, bud’ – – – – будем, budem будьте, bud’te –	– bywaj/bądź – – – – bywajmy/bądźmy bywajcie/bądźcie –	– buď – – – – buďme buďte –	– buď – – – – buďme buďte –	– bodi – bodiva bodita – bodimo bodite –	– budi (neka bude) – – – budimo budite (neka budu)	– бъди, bədi – – – – – бъдете, bədete –
Future	*bǫdǫ *bǫdešĭ *bǫdetĭ *bǫdevě *bǫdeta *bǫdete *bǫdemŭ *bǫdete *bǫdǫtĭ	bǫdǫ bǫdeši bǫdetŭ bǫdevě bǫdeta bǫdete bǫdemŭ bǫdete bǫdǫtŭ	буду, budu будеш, budeš буде(ть), bude(t') – – – будемо, budemo будете, budete будуть, budut'	буду, budu будешь, budeš' будет, budet – – – будем, budem будете, budete будут, budut	będę będziesz będzie – – – będziemy będziecie będą	budu budeš bude – – – budeme budete budou	budem budeš bude – – – budeme budete budú	bom, bodem boš, bodeš bo, bode bova, bodeva bosta, bodesta bosta, bodesta bomo bodemo boste, bodeste bodo	budem budeš bude – – – budemo budete budu	бъда, bəda бъдеш, bədeš бъде, bəde – – – бъдем, bədem бъдете, bədete бъдат, bədat
Imperfect	*běaxŭ *běaše *běaše *běaxově *běašeta *běašete *běaxomŭ *běašete *běaxǫ	– – běaše – – běašete – – běaxǫ							bijah, b(j)eh bijaše, b(j)eše bijaše, b(j)eše – – – bijasmo, b(j)esmo bijaste, b(j)este bijahu, b(j)ehu	бях, bjah беше, beše беше, beše – – – бяхме, bjahme бяхте, bjahte бяха, bjaha
Imperfective aorist	*běxŭ *bě *bě *běxově *běsta *běste *běxomŭ *běste *běšę	běxŭ bě bě *běxově *běsta běste běxomŭ *běste běšę								бях, bjah бе, be бе, be – – – бяхме, bjahme бяхте, bjahte бяха, bjaha
Perfective aorist	*byxŭ *by(stŭ?) *by(stŭ?) *byxově *bysta *byste *byxomŭ *byste *byšę	byxŭ by(stŭ) by(stŭ) byxově bysta byste byxomŭ byste byšę				bych bys by – – – bychom byste by		(bi) bi bi (bi) (bi) (bi) (bi) (bi) (bi)	bih bi bi – – – bismo biste biše	бих, bih би, bi би, bi – – – бихме, bihme бихте, bihte биха, biha
Present active participle	*sy m. *sǫťi f. *sy n.	sy m. sǫšti f. sy n.
Future active participle	*bǫdy m. *bǫdǫťi f. *bǫdy n.	bǫdy m. bǫdǫšti f. bǫdy n.	будучий, budučyj m. будуча, buduča f. будуче, buduče n.	будущий, buduščij m. будущая, buduščaja f. будущее, buduščeje n.	będący m. będąca f. będące n.	budoucí m. budoucá f. budouce n.	budúci m. budúca f. budúce n.	bodoči m. bodoča f. bodoče n.	budući m. buduća f. buduće n.	бъдещ, bədešt m. бъдещ, bədeštа f. бъдеще, bədešte n.
Past active participle	*byvŭ m. *byvŭši f. *byvŭ n.	byvŭ m. byvŭši f. byvŭ n.	бувший, buvšyj m. бувша, buvša f. бувше, buvše n.	бывший, byvšij m. бывшая, byvšaja f. бывшее, byvšeje n.	bywszy m. bywsza f. ? n.			bivši m. bivša f. bivše n.	bivši m. bivša f. bivše n.	бивш, bivš m. бивша, bivša f. бивше, bivše n.
Resultative participle	*bylŭ m. *byla f. *bylo n.	bylŭ m. byla f. bylo n.	був, buv m. була, bula f. було, bulo n.	был, byl m. была, byla f. было, bylo n.	był m. była f. było n.	byl m. byla f. bylo n.	bol m. bola f. bolo n.	bil m. bila f. bilo n.	bio m. bila f. bilo n.	бил, bil била, bila било, bilo

• In Russian, the present forms are archaic and no longer in common use, except for the third person forms, which are used in "there is/are" type phrases.
• In Serbo-Croatian the forms jesam, jesi, jeste and so on are used as the basic form of the Present Tense "to be" (i.e. I am, you are etc.), while the forms budem, budeš, bude etc. are used only for the formation of the Future Perfect.

Baltic languages

	Lithuanian	Latvian	Old Prussian
Infinitive	būti	būt
Present	esu, esmi (rare), būnu esi, būni (rare) yra, esti, esa (rare), būna esame, būname (rare) esate, būnate (rare) yra, esti (rare), esa (rare), būna (rare)	esmu, esu (vernacular) esi ir esam esat ir
Past simple	buvau buvai buvo buvome buvote buvo	biju biji bija bijām bijāt bija
Past active participle	buvęs (m. sg.) buvusi (f. sg.) buvę (m. pl.) buvusios (f. pl.)	bijis (m. sg.) bijusi (f. sg.) bijuši (m. pl.) bijušas (f. pl.)
Future	būsiu būsi bus būsime būsite bus	būšu būsi būs būsim būsiet, būsit būs
Imperative	– būk – būkime būkite –	– esi – būsim esiet –
Quotative		esot, būšot
Conditional	būčiau būtum būtų būtumėme būtumėte būtų	būtu

In Lithuanian, the paradigm būnu, būni, būna, etc. is not considered archaic or dialectal but rather a special use of the verb būti, to be, mostly used to describe repeated actions or states, or habits.

Celtic languages

In the Celtic languages there is a distinction between the so-called substantive verb, used when the predicate is an adjective phrase or prepositional phrase, and the so-called copula, used when the predicate is a noun.

The conjugation of the Old Irish and Middle Welsh verbs is as follows:

	Old Irish substantive verb	Old Irish copula	Middle Welsh
Present	(at)·tó (at)·taí (at)·tá (at)·taam (at)·taïd (at)·taat	am at is ammi adib it	wyf wyt yw, mae, taw, oes ym ych ynt, maen(t)
Preterite	·bá ·bá ·boí ·bámmar ·baid ·bátar	basa basa ba bommar unattested batar	buum buost bu buam buawch buant
Future	bia bie bieid, ·bia beimmi, ·biam bethe, ·bieid bieit, ·biat	be be bid bimmi unattested bit	bydaf bydy byd bydwn bydwch bydant

The forms of the Old Irish present tense of the substantive verb, as well as Welsh taw, come from the PIE root *stā-. The other forms are from the roots *es- and *bhū-. Welsh mae originally meant "here is" (cf. yma 'here').

Irish and Scottish Gaelic

In modern Gaelic, person inflections have almost disappeared, but the negative and interrogative are marked by distinctive forms. In Irish, particularly in the south, person inflections are still very common for the tá/bhí series.

^{[note 1]}

The Verb Bí

		Scottish Gaelic	Irish
Present	affirmative interrogative negative negative interrogative	tha a bheil chan eil nach eil	tá (1 táim, 2 táir, 3 tá, 1pl táimíd, 2pl (archaic) táthaoi, 3pl táid) an bhfuil níl (ní fhuil) nach bhfuil (1 fuilim, 2 fuilir, 3 fuil, 1pl fuilimíd-fuileam, 2pl (archaic) fuiltaoi, 3pl fuilid)
Past	affirmative interrogative negative negative interrogative	bha an robh cha robh nach robh	bhí (1 bhíos, 2 bhís, 3 bhí, 1pl bhiomair, 2pl bhíobhair, 3pl bhíodar) an raibh ní raibh nach raibh (1 rabhas, 2 rabhais, 3 raibh, 1pl rabhamair, 2pl rabhabhair, 3pl rabhadar)
Future	affirmative interrogative negative negative interrogative	bidh (or "bithidh") am bi cha bhi nach bi	beidh (1 bead, 2 beir, 3 beidh, 1pl beimíd, 2pl beidh sibh, 3pl beid) an mbeidh ní bheidh nach mbeidh

The Copula

		Scottish Gaelic		Irish
		Before a consonant	Before a vowel	Before a consonant	Before a vowel
Present	affirmative interrogative negative negative interrogative	is		is an ní nach	is an ní nach
Past/Conditional	affirmative interrogative negative negative interrogative	bu		ba ar níor nár	b' arbh níorbh nárbh

^[5]

Gaelic (bh)eil and Irish (bh)fuil are from Old Irish fuil, originally an imperative meaning "see!" (PIE root *wel-, also in Welsh gweled, Germanic wlitu- "appearance", and Latin voltus "face"), then coming to mean "here is" (cf. French voici < vois ci and voilà < vois là), later becoming a suppletive dependent form of at-tá. Gaelic robh and Modern Irish raibh are from the perfective particle ro (ry in Welsh) plus ba (lenited after ro).

Modern Welsh

The present tense in particular shows a split between the North and the South. Though the situation is undoubtedly more complicated, King (2003) notes the following variations in the present tense as spoken (not as written according to the standard orthography):

		Affirmative (I am)		Interrogative (Am I?)		Negative (I am not)
		Singular	Plural	Singular	Plural	Singular	Plural
North	First Person	dw	dan	ydw?	ydan?	(dy)dw	(dy)dan
	Second Person	—, (r)wyt	dach	wyt?	(y)dach?	dwyt	(dy)dach
	Third Person	mae	maen	ydy?	ydyn?	dydy	dydyn
South	First Person	rw, w	ŷn, —	ydw?	ŷn?	(d)w	ŷn
	Second Person	—, (r)wyt	ych	wyt?	ych?	—	(ych)
	Third Person	mae	maen	ydy?, yw?	ŷn?	dyw	ŷn

Note that, for example, the spoken first person singular dw i'n is a contraction of the formal written yr ydwyf fi yn . The Welsh F /v/ is the fricative analogue of the nasal /m/, the PIE suffix consonsant for the first person singular.

		Affirmative (I am)		Interrogative (Am I?)		Negative (I am not)
		Singular	Plural	Singular	Plural	Singular	Plural
Preterite	First Person	bues	buon	fues?	fuon?	fues	fuon
	Second Person	buest	buoch	fuest?	fuoch?	fuest	fuoch
	Third Person	buodd	buon	fuodd?	fuon?	fuodd	fuon
Imperfect	First Person	roeddwn	roedden	oeddwn?	oedden?	doeddwn	doedden
	Second Person	roeddet	roeddech	oeddet?	oeddech?	doeddet	doeddech
	Third Person	roedd	roeddyn	oedd?	oeddyn?	doedd	doeddyn
Future	First Person	bydda	byddwn	fydda?	fyddwn?	fydda	fyddwn
	Second Person	byddi	byddwch	fyddi?	fyddwch?	fyddi	fyddwch
	Third Person	bydd	byddan	fydd?	fyddan?	fydd	fyddan

Bod also has a conditional, for which there are two stems. The bas- stem is more common in the North, and the bydd- stem is more common in the South:

		Affirmative		Interrogative		Negative
		Singular	Plural	Singular	Plural	Singular	Plural
bydd-	First Person	byddwn	bydden	fyddwn	fydden	fyddwn?	fydden?
	Second Person	byddet	byddech	fyddet	fyddech	fyddet?	fyddech?
	Third Person	byddai	bydden	fyddai	fydden	fyddai?	fydden?
bas-	First Person	baswn	basen	faswn	fasen	faswn?	fasen?
	Second Person	baset	basech	faset	fasech	faset?	fasech?
	Third Person	basai	basen	fasai	fasen	fasai?	fasen?

Armenian

The Classical Armenian present tense derives from PIE *h₁es- (cf. sg. h₁esmi, h₁essi, h₁esti; 3rd pl. h₁s-énti).^[6]

	present
1st sg.	em
2nd sg.	es
3rd sg.	ē
1st pl.	emkʿ
2nd pl.	ēkʿ
3rd pl.	en

Albanian

The Albanian copula shows two distinct roots. The present jam ‘I am’ is an athematic root stem built from PIE *h₁es-. The imperfect continues the same root, with the singulars from the PIE imperfect and the plurals from the optative. The perfect, on the other hand, comes from the thematic aorist of PIE *kʷleu- ‘turn’ (cf. Ancient Greek épleto ‘he turned’, Armenian eɫew ‘he became’, Old Irish cloïd ‘turns back, defeats’).

	PIE	present	PIE → PAlb	imperfect (Cham dialect)	PIE → PAlb	perfect
1st sg.	*h₁ésmi	jam	*h₁és-m̥ → ésa	isha (jeshë)	*kʷleu-s-m̥ → klesa	qeshë
2nd sg.	*h₁ési	je	*h₁és-e-t → éset	ishë (jeshë)	*kʷleu-s → kles	qe
3rd sg.	*h₁ésti	është	*h₁és-t → ést	ish	*kʷleu-t → klet	qe
1st pl.	*h₁s-méi	jemi	*h₁es-ī́me → esīm	ishim (jeshëm)	*kʷleu-mé → kleme	qemë
2nd pl.	*esi (2nd sg.) + -ni	jeni	*h₁es-ī́te → esīt	ishit (jeshëtë)	*kʷleu-té → klete	qete
3rd pl.	*h₁s-nti	janë	*h₁es-íjnt → esīnt	ishin (ishnë)	*kʷleu-nti → klenti	qenë

See also

• Grammatical conjugation

Notes

References

v t e Proto-Indo-European language Phonology Accent Centum-satem isogloss Glottalic theory Laryngeal theory s-mobile Sound laws boukólos rule kʷetwóres rule Grassmann's Osthoff's Pinault's Siebs' Sievers' Stang's Szemerényi's Morphology Ablaut Caland system h₂e-conjugation Nasal infix Root Thematic vowel Narten present Parts of speech Nominals (nouns and adjectives) Numerals Particles Pronouns Verbs copula Vocabulary See also Proto-Indo-European religion Proto-Indo-European society Indo-European studies