Proto-Celtic language

The Proto-Celtic language, also called Common Celtic, is the partially reconstructed proto-language of all the known Celtic languages. Its lexis, or vocabulary, can be confidently reconstructed on the basis of the comparative method of historical linguistics, in the same manner as Proto-Indo-European, the proto-language which has been most thoroughly reconstructed. Proto-Celtic is a descendant of the Proto-Indo-European language and is itself the ancestor of the Celtic languages which are members of the modern Indo-European language family, the most commonly spoken language family. Modern Celtic languages share common features with Italic languages that are unseen in other branches and according to one theory they may have formed an ancient Italo-Celtic branch. The duration of the cultures speaking Proto-Celtic was relatively brief compared to PIE’s 2,000 years. By the Iron Age Hallstatt cultureof around 800 BC these people had become fully Celtic.

The reconstruction of Proto-Celtic is currently being undertaken, by necessity relying on later iterations of Celtic languages. Although Continental Celtic presents much substantiation for Proto-Celtic phonology, and some for its morphology, recorded material is too scanty to allow a secure reconstruction of syntax, although some complete sentences are recorded in the Continental Gaulish and Celtiberian. Therefore, the primary sources for reconstruction come from the Insular Celtic languages with the oldest literature found in Old Irish and Middle Welsh, dating back to authors flourishing in the 6th century CE.

Dating

Proto-Celtic is mostly dated to the Late Bronze Age, ca. 1200–900 BCE. The word for ‘iron’, traditionally reconstructed to Proto-Celtic as *īsarnom, in particular, has long been taken as an indication that the divergence into individual Celtic languages did not start until the Iron Age (the 8th century BC at the latest), but Schumacher and Schrijver have proposed to date Proto-Celtic as early as the 13th century BC, the time of the Canegrate culture, in northwestern Italy, and the Urnfield culture in Central Europe, implying that the divergence may have already started in the Bronze Age.

Sound changes from Proto-Indo-European

The phonological changes from Proto-Indo-European to Proto-Celtic may be summarised as follows. The changes are roughly in chronological order, with changes that operate on the outcome of earlier ones appearing later in the list.

Late Proto-Indo-European

These changes were shared by several other Indo-European branches.

  • *e is colored by an adjacent laryngeal consonant:
    • eh₂, h₂e > ah₂, h₂a
    • eh₃, h₃e > oh₃, h₃o
  • Palatovelars merge into the plain velars:
    • ḱ > k
    • ǵ > g
    • ǵʰ > gʰ
  • Epenthetic *a is inserted after a syllabic sonorant if a laryngeal and another sonorant follow (R̥HR > RaHR)
  • Laryngeals are lost:
    • before a following vowel (HV > V)
    • following a vowel in syllables before the accent (VHC´ > VC´)
    • following a vowel, resulting in compensatory lengthening, thus (VH > V̄)
    • between plosives in non-initial syllables (CHC > CC)
  • Two adjacent dentals become two adjacent sibilants (TT > ss)

Italo-Celtic

The following sound changes are shared with the Italic languages in particular, and are cited in support of the Italo-Celtic hypothesis.

  • Dybo’s rule: long close vowels are shortened (or a laryngeal is lost) before resonant + stressed vowel.
    • īR´ / ? *iHR´ > iR´
    • ūR´ / ? *uHR´ > uR´
  • Possibly, post-consonantal laryngeals are lost when before pre-tonic close vowels:
    • CHiC´ > CiC´
    • CHuC´ > CuC´
  • Development of initial stress, following the previous two changes.
  • Possibly, vocalization of laryngeals to *ī between a *CR cluster and consonantal *j (CRHjV > CRījV)
  • Syllabic laryngeals become *a (CHC > CaC)
  • Syllabic resonants before a voiced unaspirated stop become *Ra (R̥D > RaD)
  • *m is assimilated or lost before a glide:
    • mj > nj
    • mw > w
  • *p assimilates to *kʷ when another *kʷ follows later in the word (p…kʷ > kʷ…kʷ)
  • sVs > ss, sTVs > Ts

One change shows non-exact parallels in Italic: the vocalization of syllabic resonants next to laryngeals depending on the environment. Similar developments appear in Italic, but for the syllabic nasals *m̥, *n̥, the result is Proto-Italic *əm, *ən (> Latin em ~ imen ~ in).

  • Word-initially, HR̥C > aRC
  • Before voiceless stops, CR̥HT > CRaT
  • CR̥HV > CaRHV
  • CR̥HC > CRāC

Early Proto-Celtic

  • Sequences of velar and *w merge into the labiovelars (it is uncertain if this preceded or followed the next change; that is, whether gw > b or gw > gʷ, but Schumacher 2004 argues on p. 372 that this change came first; moreover, it is also found in Proto-Italic, and thus arguably belongs to the previous section):
    • kw > kʷ
    • gw > gʷ
    • gʰw > gʷʰ
  • gʷ > b
  • Aspirated stops lose their aspiration and merge with the voiced stops (except that this counterfeeds the previous change, so *gʷʰ > *gʷ doesn’t result in a merger):
    • bʰ > b
    • dʰ > d
    • gʰ > g
    • gʷʰ > gʷ
  • *e before a resonant and *a (but not *ā) becomes *a as well (eRa > aRa): *ǵʰelH-ro > *gelaro > *galaro / *gérH-no > *gerano > *garano (Joseph’s rule).
  • Epenthetic *i is inserted after syllabic liquids when followed by a plosive:
    • l̥T > liT
    • r̥T > riT
  • Epenthetic *a is inserted before the remaining syllabic resonants:
    • m̥ > am
    • n̥ > an
    • l̥ > al
    • r̥ > ar
  • All remaining nonsyllabic laryngeals are lost.
  • ē > ī
  • ō > ū in final syllables
  • Long vowels are shortened before a syllable-final resonant (V:RC > VRC); this also shortens long diphthongs. (Osthoff’s law)

Late Proto-Celtic

  • Plosives become *x before a different plosive or *s (C₁C₂ > xC₂, Cs > xs)
  • p > b before liquids (pL > bL)
  • p > w before nasals (pN > wN)
  • p > ɸ (except possibly after *s)
  • ō > ā
  • ew > ow
  • uwa > owa

Examples

PIE Proto-Celtic Example
Proto-Celtic Old Irish Welsh
*p *ɸ *ph₂tḗr > *ɸatīr ‘father’ athir cf. edrydd “home” (< *ɸatrijo-)
*t *t *tréyes > *trīs ‘three’ trí tri
*k, ḱ *k *kh₂n̥-e- > *kan-o- ‘sing’
*ḱm̥tom > *kantom ‘hundred’
canaid
cét /kʲeːd/
canu
cant
* * *kʷetwr̥es > *kʷetwares ‘four’ ceth(a)ir pedwar
*b *b *h₂ébōl > *abalom ‘apple’ uball afal
*d *d *derḱ- > *derk- ‘see’ derc “eye” drych “sight”
*g, ǵ *g *gleh₁i- > *gli-na- ‘to glue’
*ǵen-u- > *genu- ‘jaw’
glen(a)id “(he) sticks fast”
giun, gin “mouth”
glynu “adhere”
gên “jaw”
* *b *gʷenh₂ > *bena ‘woman’ ben OW ben
* *b *bʰére- > *ber-o- ‘carry’ berid “(he) carries” adfer “to restore”, cymeryd “to take”
* *d *dʰeh₁i- > *di-na- ‘suck’ denait “they suck” dynudenu
*gʰ, ǵʰ *g *gʰh₁bʰ-(e)y- > *gab-i- ‘take’
*ǵʰelH-ro- > *galaro- ‘sickness’
ga(i)bid “(he) takes”
galar
gafael “hold”
galar “grief”
*gʷʰ * *gʷʰn̥- > *gʷan-o- ‘kill, wound’ gonaid “(he) wounds, slays” gwanu “stab”
*s *s *sen-o- > *senos ‘old’ sen hen
*m *m *méh₂tēr > *mātīr ‘mother’ máthir cf. modryb “aunt”
*n *n *h₂nép-ōt- > *neɸūts ‘nephew’ niad nai
*l *l *leyǵʰ- > *lig-e/o- ‘lick’ ligid “(he) licks” llyo, llyfu
*r *r *h₃rēǵ-s > *rīgs ‘king’  (gen. ríg) rhi
*j *j *h₂yuh₁n-ḱós > *juwankos ‘young’ óac ieuanc
*w *w *h₂wl̥h₁tí- > *wlatis ‘rulership’ flaith gwlad “country”
PIE Proto-Celtic Example
Proto-Celtic Old Irish Welsh
*a, h₂e *a *h₂ep-h₃ōn- > *abū (acc. *abonen) ‘river’ aub afon
*ā, *eh₂ *ā *bʰréh₂tēr > *brātīr ‘brother’ bráthir brawd
*e, h₁e *e *sen-o- > *senos ‘old’ sen hen
*H (any laryngeal H between consonants) *a *ph₂tḗr > *ɸatīr ‘father’ athir cf. edrydd “home”
*ē, eh₁ *ī *weh₁-ro- > *wīros ‘true’ fír gwir
*o, Ho, h₃e *o *Hroth₂o- > *rotos ‘wheel’ roth rhod
*ō, eh₃ in final syllable, *ū *h₂nép-ōt- > *neɸūts ‘nephew’ niæ nai
elsewhere, *ā *deh₃no- > *dāno- ‘gift’ dán dawn
*i *i *gʷih₃-tu- > *bitus ‘world’ bith byd
*ī, iH *ī *rīmeh₂ > *rīmā ‘number’ rím rhif
*ai, h₂ei, eh₂i *ai *kaikos > *kaikos ‘blind’
*seh₂itlo- > *saitlo- ‘age’
cáech “one-eyed”
coeg “empty, one-eyed”
hoedl
*(h₁)ei, ēi, eh₁i *ei *deywos > *deiwos ‘god’ día duw
*oi, ōi, h₃ei, eh₃i *oi *oynos > *oinos ‘one’ óen oín; áen aín un
*u before wao *h₂yuh₁n-ḱós > early *juwankos > late *jowankos ‘young’ óac ieuanc
elsewhere, *u *srutos > *srutos ‘stream’ sruth ffrwd
*ū, uH *ū *ruHneh₂ > *rūnā ‘mystery’ rún rhin
*au, h₂eu, eh₂u *au *tausos > *tausos ‘silent’ táue “silence” < *tausijā taw
*(h₁)eu, ēu, eh₁u;
*ou, ōu, h₃eu, eh₃u
*ou *tewteh₂ > *toutā ‘people’
*gʷeh₃-u-s > *bows ‘cow’
túath
tud
MW bu, biw
* before stops, *li *pl̥th₂nós > *ɸlitanos ‘wide’ lethan llydan
before other consonants, *al *kl̥h₁- > *kaljākos ‘rooster’ cailech (Ogam gen. caliaci) ceiliog
*r̥ before stops, *ri *bʰr̥ti- > *briti- ‘act of bearing; mind’ breth, brith bryd
before other consonants, *ar *mr̥wos > *marwos ‘dead’ marb marw
* *am *dm̥-nh₂- > *damna- ‘subdue’ MIr damnaid “he ties, fastens, binds”
* *an *h₃dn̥t- > *danton ‘tooth’ dét /dʲeːd/ dant
*l̥H before obstruents, *la *h₂wlh₁tí- > *wlatis ‘lordship’ flaith gwlad “country”
before sonorants, * *pl̥Hmeh₂ > *ɸlāmā ‘hand’ lám llaw
*r̥H before obstruents, *ra *mr̥Htom > *mratom ‘betrayal’ mrath brad
before sonorants, * *ǵr̥Hnom > *grānom ‘grain’ grán grawn
*m̥H *am/mā
(presumably same distribution as above)
*dm̥h₂-ye/o- > *damje/o- ‘to tame’ daimid “endures, suffers; submits to, permits”, fodam- goddef “endure, suffer”
*n̥H *an or *
(presumably same distribution as above)
probably *ǵn̥h₃to- > *gnātos ‘known’ gnáth gnawd“customary”

Phonological reconstruction

Consonants

The following consonants have been reconstructed for Proto-Celtic:

Type  Bilabial  Alveolar  Palatal  Velar
plain labialized
Plosive b t d k ɡ kʷ ɡʷ
Nasal m n
Fricative ɸ s x
Approximant l j w
Trill r

In contrast to the parent language, Proto-Celtic does not use aspiration as a feature for distinguishing phonemes. So the Proto-Indo-European voiced aspirated stops *, *, *gʰ/ǵʰmerged with *b, *d, *g/ǵ. The voiced aspirate labiovelar *gʷʰ did not merge with *, though: plain * became *b in Proto-Celtic, while aspirated *gʷʰ became *. Thus, PIE *gʷen-‘woman’ became Old Irish ben and Old Welsh ben, but PIE *gʷʰn̥- ‘to kill, to wound’ became Old Irish gonaid and Welsh gwanu.

Proto-Indo-European *p was lost in Proto-Celtic, apparently going through the stages *ɸ (as in the table above) and *h (perhaps attested by the toponym Hercynia if this is of Celtic origin) before being lost completely word-initially and between vowels. Adjacent to consonants, Proto-Celtic *ɸ underwent different changes: the clusters *ɸs and *ɸt became *xs and *xt respectively already in Proto-Celtic. PIE *sp- became Old Irish s (lenited f-, exactly as for PIE *sw-) and Brythonic f; while Schrijver 1995, p. 348 argues there was an intermediate stage *sɸ- (in which *ɸ remained an independent phoneme until after Proto-Insular Celtic had diverged into Goidelic and Brythonic), McCone 1996, pp. 44–45 finds it more economical to believe that *sp- remained unchanged in PC, that is, the change *p to *ɸ did not happen when *s preceded. (Similarly, Grimm’s law did not apply to *p, t, k after *s in Germanic, and later the same exception occurred again in the High German consonant shift.)

Proto-Celtic Old Irish Welsh
*laɸs- > *laxs- ‘shine’ las-aid llach-ar
*seɸtam > *sextam ‘seven’ secht saith
*sɸeret- or *speret- ‘heel’ seir ffêr

In Gaulish and the Brittonic languages, a new *p sound has arisen as a reflex of the Proto-Indo-European * phoneme. Consequently, one finds Gaulish petuar, Welsh pedwar“four”, compared to Old Irish cethair and Latin quattuor. Insofar as this new /p/ fills the space in the phoneme inventory which was lost by the disappearance of the equivalent stop in PIE, we may think of this as a chain shift.

The terms P-Celtic and Q-Celtic are useful when we wish to group the Celtic languages according to the way they handle this one phoneme. However a simple division into P- and Q-Celtic may be untenable, as it does not do justice to the evidence of the ancient Continental Celtic languages. The large number of unusual shared innovations among the Insular Celtic languages are often also presented as evidence against a P-Celtic vs Q-Celtic division, but they may instead reflect a common substratum influence from the pre-Celtic languages of Britain and Ireland,, or simply continuing contact between the insular languages; in either case they would be irrelevant to Celtic language classification in the genetic sense.

Q-Celtic languages may also have /p/ in loan words, though in early borrowings from Welsh into Primitive Irish /kʷ/ was used by sound substitution due to a lack of a /p/ phoneme at the time:

  • Latin Patricius “Saint Patrick”‘ > Welsh > Primitive Irish Qatrikias > Old Irish Cothrige, later Pádraig;
  • Latin presbyter “priest” > early form of word seen in Old Welsh premter primter > Primitive Irish qrimitir > Old Irish cruimther.

Gaelic póg “kiss” was a later borrowing (from the second word of the Latin phrase osculum pacis “kiss of peace”) at a stage where p was borrowed directly as p, without substituting c.

Vowels

The Proto-Celtic vowel system is highly comparable to that reconstructed for Proto-Indo-European by Antoine Meillet. The following monophthongs have been reconstructed:

Type Front Central Back
long short long short long short
Close i u
Mid e o
Open a

The following diphthongs have also been reconstructed:

 
Type With -i With -u
With e- ei
With a- ai au
With o- oi ou

Morphology

Nouns

The morphology (structure) of nouns and adjectives demonstrates no arresting alterations from the parent language. Proto-Celtic is believed to have had nouns in three genders, three numbers and five to eight cases. The genders were the normal masculine, feminine and neuter, the three numbers were singular, plural and dual. The number of cases is a subject of contention: while Old Irish may have only five, the evidence from Continental Celtic is considered rather unambiguous despite appeals to archaic retentions or morphological leveling. These cases were nominative, vocative, accusative, dative, genitive, ablative, locative and instrumental.

Nouns fall into nine or so declensions, depending on the stem. There are *o-stems, *ā-stems, *i-stems, *u-stems, dental stems, velar stems, nasal stems, *r-stems and *s-stems.

*o-stem nouns

  • makkʷos ‘son’ (masculine) (Old Irish mac ~ Welsh, Cornish and Breton mab)
Case Singular Dual Plural
Nominative *makkʷos *makkʷou *makkʷoi
Vocative *makkʷe *makkʷou *makkʷūs
Accusative *makkʷom *makkʷou *makkʷūs
Genitive *makkʷī *makkʷūs *makkʷom
Dative *makkʷūi *makkʷobom *makkʷobos
Ablative *makkʷū *makkʷobim *makkʷobis
Instrumental *makkʷū *makkʷobim *makkʷūs
Locative *makkʷei *makkʷou *makkʷobis
  • dūnom ‘stronghold’ (neuter)
Case Singular Dual Plural
Nominative *dūnom *dūnou *dūnā
Vocative *dūnom *dūnou *dūnā
Accusative *dūnom *dūnou *dūnā
Genitive *dūnī *dūnūs *dūnom
Dative *dūnūi *dūnobom *dūnobos
Ablative *dūnū *dūnobim *dūnobis
Instrumental *dūnū *dūnobim *dūnūs
Locative *dūnei *dūnou *dūnobis

*ā-stem nouns

E.g. *ɸlāmā ‘hand’ (feminine) (Old Irish lám; Welsh llaw, Cornish leuv, Old Breton lom)

Case Singular Dual Plural
Nominative *ɸlāmā *ɸlāmai *ɸlāmās
Vocative *ɸlāmā *ɸlāmai *ɸlāmās
Accusative *ɸlāmām *ɸlāmai *ɸlāmās
Genitive *ɸlāmās *ɸlāmajous *ɸlāmom
Dative *ɸlāmāi *ɸlāmābom *ɸlāmābos
Ablative *ɸlāmī *ɸlāmābim *ɸlāmābis
Instrumental *ɸlāmī *ɸlāmābim *ɸlāmābis
Locative *ɸlāmāi *ɸlāmābim *ɸlāmābis

E.g. *wolkās ‘hawker’ (masculine) (Gallic Latinised Volcae)

Case Singular Dual Plural
Nominative *wolkās *wolkai *wolkās
Vocative *wolkā *wolkai *wolkās
Accusative *wolkām *wolkai *wolkās
Genitive *wolkās *wolkajous *wolkom
Dative *wolkāi *wolkābom *wolkābos
Ablative *wolkī *wolkābim *wolkābis
Instrumental *wolkī *wolkābim *wolkābis
Locative *wolkāi *wolkābim *wolkābis

*i-stems

E.g. *sūlis ‘sight, view, eye’ (feminine) (Brittonic sulis ~ Old Irish súil)

Case Singular Dual Plural
Nominative *sūlis *sūlī *sūlīs
Vocative *sūli *sūlī *sūlīs
Accusative *sūlim *sūlī *sūlīs
Genitive *sūleis *sūljous *sūljom
Dative *sūlei *sūlibom *sūlibos
Ablative *sūlī *sūlibim *sūlibis
Instrumental *sūlī *sūlibim *sūlibis
Locative *sūlī *sūlibim *sūlibis

E.g. *mori ‘body of water, sea’ (neuter) (Gallic Mori– ~ Old Irish muir ~ Welsh môr)

Case Singular Dual Plural
Nominative *mori *morī *morjā
Vocative *mori *morī *morjā
Accusative *mori *morī *morjā
Genitive *moreis *morjous *morjom
Dative *morei *moribom *moribos
Ablative *morī *moribim *moribis
Instrumental *morī *moribim *moribis
Locative *morī *moribim *moribis

*u-stem nouns

E.g. *bitus ‘world, existence’ (masculine) (Gallic Bitu– ~ Old Irish bith ~ Welsh byd ~ Breton bed)

Case Singular Dual Plural
Nominative *bitus *bitou *bitowes
Vocative *bitu *bitou *bitowes
Accusative *bitum *bitou *bitūs
Genitive *bitous *bitowou *bitowom
Dative *bitou *bitubom *bitubos
Ablative *bitū *bitubim *bitubis
Instrumental *bitū *bitubim *bitubis
Locative *bitū *bitubim *bitubis

E.g. *dānu ‘valley river’ (neuter?)

Case Singular Dual Plural
Nominative *dānu *dānou *dānwā
Vocative *dānu *dānou *dānwā
Accusative *dānu *dānou *dānwā
Genitive *dānous *dānowou *dānowom
Dative *dānou *dānubom *dānubos
Ablative *dānū *dānubim *dānubis
Instrumental *dānū *dānubim *dānubis
Locative *dānū *dānubim *dānubis

Velar and dental stems

Before the *-s of the nominative singular, a velar consonant was fricated to *-x : *rīg– “king” > *rīxs. Likewise, final *-d devoiced to *-t-: *druwid– “druid” > *druwits.

E.g. *rīxs ‘king’ (masculine) (Gallic –rix; Old Irish ; Middle Welsh rhi, Old Breton riGermanic *-riks, as seen in Haimariks, ancestor of the name “Henry” and related forms)

Case Singular Dual Plural
Nominative *rīxs *rīge *rīges
Vocative *rīxs *rīge *rīges
Accusative *rīgam *rīge *rīgās
Genitive *rīgos *rīgou *rīgom
Dative *rīgei *rīgobom *rīgobos
Ablative *rīgī *rīgobim *rīgobis
Instrumental *rīge *rīgobim *rīgobis
Locative *rīgi *rīgobim *rīgobis

E.g. *druwits ‘druid’ (masculine) (Gallic druis; Old Irish druí; Middle Welsh dryw “druid; wren”, Old Cornish druw)

Case Singular Dual Plural
Nominative *druwits *druwide *druwides
Vocative *druwits *druwide *druwides
Accusative *druwidem *druwide *druwidās
Genitive *druwidos *druwidou *druwidom
Dative *druwidei *druwidobom *druwidobos
Ablative *druwidī *druwidobim *druwidobis
Instrumental *druwide *druwidobim *druwidobis
Locative *druwidi *druwidobim *druwidobis

E.g. *karnuxs ‘carnyx’ (masculine?)

Case Singular Dual Plural
Nominative *karnuxs *karnuke *karnukes
Vocative *karnuxs *karnuke *karnukes
Accusative *karnukam *karnuke *karnukās
Genitive *karnukos *karnukou *karnukom
Dative *karnukei *karnukobom *karnukobos
Ablative *karnukī *karnukobim *karnukobis
Instrumental *karnuke *karnukobim *karnukobis
Locative *karnuki *karnukobim *karnukobis

E.g. *karants ‘friend’ (masculine) (Gallic carant-; Old Irish cara; Welsh câr “kinsman; friend”, pl. ceraint, Breton kar “relative”, pl. kerent)

Case Singular Dual Plural
Nominative *karants *karante *karantes
Vocative *karants *karante *karantes
Accusative *karantam *karante *karantās
Genitive *karantos *karantou *karantom
Dative *karantei *karantobom *karantobos
Ablative *karantī *karantobim *karantobis
Instrumental *karante *karantobim *karantobis
Locative *karanti *karantobim *karantobis

Nasal stems

Generally, nasal stems end in *-on-; this becomes *-ū in the nominative singular: *abon- “river” > *abū.

E.g. *abū ‘river’ (feminine) (Welsh afon, Breton (obs.) aven, Scottish Gaelic abhainn)

Case Singular Dual Plural
Nominative *abū *abone *abones
Vocative *abū *abone *abones
Accusative *abonam *abone *abonās
Genitive *abonos *abonou *abonom
Dative *abonei *abnobom *abnobos
Ablative *abonī *abnobim *abnobis
Instrumental *abone *abnobim *abnobis
Locative *aboni *abnobim *abnobis

E.g. *anman ‘name’ (neuter) (Gaulish anuan-; Old Irish ainm; Breton anv; Welsh enw)

Case Singular Dual Plural
Nominative *anman *anmane *anmanes
Vocative *anman *anmane *anmanes
Accusative *anmanam *anmane *anmanās
Genitive *anmanos *anmanou *anmanom
Dative *anmanei *anmanobom *anmanobos
Ablative *anmanī *anmanobim *anmanobis
Instrumental *anmane *anmanobim *anmanobis
Locative *anmani *anmanobim *anmanobis

*s-stem nouns

Generally, *s-stems end in *-es-, which becomes *-os in the nominative singular: *teges– ‘house’ > *tegos.

E.g. *tegos ‘house’ (masculine), Old Irish teg, tech, dative tigh; Welsh , Breton ti.

Case Singular Dual Plural
Nominative *tegos *tegese *tegeses
Vocative *tegos *tegese *tegeses
Accusative *tegesam *tegese *tegesās
Genitive *tegesos *tegesou *tegesom
Dative *tegesei *tegesobom *tegesobos
Ablative *tegesī *tegesobim *tegesobis
Instrumental *tegese *tegesobim *tegesobis
Locative *tegesi *tegesobim *tegesobis

*r-stem nouns

  • r-stems are rare and principally confined to names of relatives. Typically they end in *-ter-, which becomes *-tīr in the nominative and *-tr– in all other cases aside from the accusative: *ɸater– ‘father’ > *ɸatīr, *ɸatros.

E.g. *ɸatīr ‘father’ (masculine)

Case Singular Dual Plural
Nominative *ɸatīr *ɸatere *ɸateres
Vocative *ɸatīr *ɸatere *ɸateres
Accusative *ɸateram *ɸatere *ɸaterās
Genitive *ɸatros *ɸatrou *ɸatrom
Dative *ɸatrei *ɸatrebom *ɸatrebos
Ablative *ɸatrī *ɸatrebim *ɸatrebis
Instrumental *ɸatre *ɸatrebim *ɸatrebis
Locative *ɸatri *ɸatrebim *ɸatrebis

E.g. *mātīr ‘mother’ (feminine)

Case Singular Dual Plural
Nominative *mātīr *mātere *māteres
Vocative *mātīr *mātere *māteres
Accusative *māteram *mātere *māterās
Genitive *mātros *mātrou *mātrom
Dative *mātrei *mātrebom *mātrebos
Ablative *mātrī *mātrebim *mātrebis
Instrumental *mātre *mātrebim *mātrebis
Locative *mātri *mātrebim *mātrebis

Verbs

From comparison between early Old Irish and Gaulish forms it seems that Continental and Insular Celtic verbs were to develop differently and so the study of Irish and Welsh may have unduly weighted past opinion of proto-Celtic verbal morphology. It can be inferred from Gaulish and Celtiberian as well as Insular Celtic that the proto-Celtic verb had at least three moods:

  • indicative — seen in e.g. 1st sg. Gaulish delgu “I hold”, Old Irish tongu “I swear”
  • imperative — seen in e.g. 3rd sg. Celtiberian usabituz, Gaulish appisetu
  • subjunctive — seen in e.g. 3rd sg. Gaulish buetid “may he be”, Celtiberian asekati

and four tenses:

  • present — seen in e.g. Gaulish uediíu-mi “I pray”, Celtiberian zizonti “they sow”
  • preterite — seen in e.g. 3rd sg. Gaulish sioxti, Lepontic KariTe
  • imperfect — perhaps in Celtiberian kombalkezatibion
  • future — seen in e.g. 3rd sg. Gaulish bissiet, Old Irish bieid “he shall be”

A probable optative mood also features in Gaulish (tixsintor) and an infinitive (with a characteristic ending -unei) in Celtiberian.

Verbs were formed by adding suffixes to a verbal stem. The stem might be thematic or athematic, an open or a closed syllable.

Example conjugations

Scholarly reconstructions  may be summarised in tabular format.

Conjugation like *bere/o- ‘bear, carry, flow’
Person Pres Impf Fut Pst
Act Pss Act Pss Act Pss Act Pss
Ind 1.sg *berū(mi) *berūr *berennem * *bibrām *bibrār *bertū *
2.sg *beresi *beretar *berītū * *bibrāsi *bibrātar *bertes *
3.sg *bereti *beretor *bere(to) *beretei *bibrāti *bibrātor *bert *brito
1.pl *beromu(snīs) *berommor *beremmets * *bibrāmes *bibrāmmor *bertomu *
2.pl *berete *beredwe *beretes (OI) ~ *bere-swīs (B) * *bibrāte *bibrādwe *bertete *
3.pl *beronti *berontor *berentets *berentits (?) *bibrānt *bibrāntor *bertont *britūnts
Sbj 1.sg *berām *berār *berānnem * * * * *
2.sg *berāsi *berātar *berātū * * * * *
3.sg *berāti *berātor *berā(to) * * * * *
1.pl *berāmes *berāmmor *berāmmets * * * * *
2.pl *berāte *berādwe *berātes (OI) ~ *berā-swīs (B) * * * * *
3.pl *berānti *berāntor *berāntets * * * * *
Imp 1.sg * * * * * * * *
2.sg *berī! *beretar! * * * * * *
3.sg *beret! *beror! * * * * * *
1.pl *beromu! *berommor! * * * * * *
2.pl *beretīs! *beredwe! * * * * * *
3.pl *beront! *berontor! * * * * * *
VN (unmarked) *berowon- * * * * * *’ *britu-s
Ptple (unmarked) *beront- *beromno- * *beretejo- * * *bertjo- *brito-
Conjugation like *mārā- ‘greaten, magnify, enlarge’
Person Pres Impf Fut Pst
Act Pss Act Pss Act Pss Act Pss
Ind 1.sg *mārāmi *mārār *mārānnem * *māriswāmi *māriswār *mārātsū *
2.sg *mārāsi *mārātar *mārātū * *māriswāsi *māriswātar *mārātssi *
3.sg *mārāti *mārātor *mārā(to) *mārātei *māriswāti *māriswātor *mārātsti *
1.pl *mārāmu(snīs) *mārāmmor *mārāmmets * *māriswāmos *māriswāmmor *mārātsomu *
2.pl *mārāte *mārādwe *mārātes (OI) ~ *mārā-swīs (B) * *māriswāte *māriswādwe *mārātsete *
3.pl *mārānti *mārāntor *mārāntets *mārāntits (?) *māriswānti *māriswāntor *mārātsont *mārātūnts (?)
Sbj 1.sg *mārām *māror *māronnem * * * * *
2.sg *mārosi *mārotar *mārotū * * * * *
3.sg *māroti *mārotor *māro(to) * * * * *
1.pl *māromes *mārommor *mārommets * * * * *
2.pl *mārote *mārodwe *mārotes (OI) ~ *māro-swīs (B) * * * * *
3.pl *māronti *mārontor *mārontets * * * * *
Imp 1.sg * * * * * * * *
2.sg *mārā! *mārātrīs! * * * * * *
3.sg *mārāt! *mārār! * * * * * *
1.pl *mārāmu! *mārāmmor! * * * * * *
2.pl *mārātīs! *mārādwe! * * * * * *
3.pl *mārānt! *mārāntor! * * * * * *
VN (unmarked) *mārāwon- * * * * * *’ *mārātu-s
Ptple (unmarked) *mārānt- *mārāmno- * *mārātejo- * * *mārātjo- *mārāto-