Celtiberian or Northeastern Hispano-Celtic is an extinct Indo-European language of the Celtic branch spoken by the Celtiberians in an area of the Iberian Peninsula between the headwaters of the Douro, Tagus, Júcar and Turia rivers and the Ebro river. This language is directly attested in nearly 200 inscriptions dated to the 2nd and 1st centuries BC, mainly in Celtiberian script, a direct adaptation of the northeastern Iberian script, but also in the Latin alphabet. The longest extant Celtiberian inscriptions are those on three Botorrita plaques, bronze plaques from Botorrita near Zaragoza, dating to the early 1st century BC, labeled Botorrita I, III and IV (Botorrita II is in Latin).
Overview
Under the P/Q Celtic hypothesis, and like its Iberian relative Gallaecian, Celtiberian is classified as a Q Celtic language, putting it in the same category as Goidelic and not P-Celtic like Gaulish or Brittonic.
Under the Insular/Continental Celtic hypothesis, Celtiberian and Gaulish are grouped together as Continental Celtic languages but this grouping is paraphyletic: no evidence suggests the two shared any common innovation separately from Insular Celtic. According to Ranko Matasovic in the introduction to his 2009 Etymological Dictionary of Proto-Celtic : "Celtiberian...is almost certainly an independent branch on the Celtic genealogical tree, one that became separated from the others very early."
Celtiberian has a fully inflected relative pronoun ios (as does, for instance, Ancient Greek), an ancient feature that was not preserved by the other Celtic languages, and the particles 'and' < *kʷe (cf. Latin -, Attic Greek te), 'nor' < *ne-kʷe (cf. Latin ), 'also, as well' < *h₂et(i)-kʷe (cf. Lat. , Gaulish ate, OIr. aith 'again'), ve "or" (cf. Latin enclitic and Attic Greek ē < Proto-Greek *ē-we). As in Welsh, there is an s-subjunctive, "he shall take" (Old Irish gabid), robiseti, auseti. Compare Umbrian ferest "he/she/it shall make" or Ancient Greek (aorist subj.) / (future ind.) "(that) he/she/it shall show".
Phonology
Celtiberian was a Celtic language that shows the characteristic sound changes of Celtic languages such as:
PIE Consonants
PIE *bʰ, *dʰ, *gʰ > b, d, g: Loss of Proto-Indo-European voiced aspiration. Celtiberian and Gaulish placename element 'hill, town, akro-polis' < *bʰr̥ǵʰ-eh₂; 'they are watered' < *nebʰ-i-nt-or; 'he must build' < *dʰingʰ-bī-tōd, 'to build around > to enclose' < *h₂m̥bi-dʰingʰ-o-mn-ei (cf. Latin 'to build, shape' < *dʰingʰ-o, Old Irish cunutgim 'erect, build up' < *kom-ups-dʰingʰ-o), '(that someone) builds around > enclose' < *h₂m̥bi-dʰingʰ-s-e-ti. 'mandatory, required' < *gʰor-ti-ka (cfr. Latin 'exhort' < *ex-gʰor-to); though, as the meaning in Celtiberian cannot be determined with certainty, this root may be related to Old Irish gort "field" (<PIE: *ghо̄rdh-s, Gen. *ghrdh-os ‘enclosure, garden, pen") and its many Indo-European cognates. 'daughter' < *dʰugh₂tēr, 'grandson, son of the daughter' (Common Celtic ); 'mine' < *bʰedʰ-yo 'that is pierced'. PIE *kʷ: Celtiberian preserved the PIE voiceless labiovelar kʷ (hence Q-Celtic), a development also observed in Archaic Irish and Latin. On the contrary Brythonic and Gaulish (P-Celtic--a change also seen in some dialects of Ancient Greek and some Italic branches like P-Italic) changed kʷ to p. -kue 'and' < *kʷe, Latin -que, Osco-Umbrian -pe 'and', neip 'and not, neither' < *ne-kʷe. PIE *ḱw > ku: horse (in ethnic name ekualakos) < *h₁eḱw-ālo (cf. Middle Welsh ebawl 'foal' < *epālo, Latin 'horse', OIr. ech 'horse' < *eko´- < *h₁eḱwo-, OBret. eb < *epo- < *h₁eḱwo-); 'dog' < *kuu < *kwōn, in , 'hound-man, male hound/wolf, werewolf' (cfr. Old Irish Ferchú < *Virokū, Old Welsh Gurcí < *Virokū 'idem.'. PIE *gʷ > b: bindis 'legal agent' < *gʷiHm-diks (cfr. Latin vindex 'defender'); 'cow passage' < *gʷow-(e)ito (cfr. OIr bòthar 'cow passage' < *gʷow-(e)itro), and boustom 'cowshed' < *gʷow-sto. PIE *gʷʰ > gu: < *gʷʰedʰ-y-ont 'imploring, pleading'. Common Celtic 'ask, plead, pray', OIr. guidid, W. . PIE *p > *φ > ∅: Loss of PIE *, e.g. (Celtiberian, Old Irish and Old Breton) vs. Latin and Sanskrit . acc. pl. fem. 'six feet, unit of measure' (< *φodians < *pod-y-ans *sweks); 'stone building' < *pl̥-ya (cfr. OIr. ail 'boulder'); 'higher' < *uφamos < *up-m̥os; 'remainder, rest' < *uper-n̥tiyo (cfr. Latin ). Toponym now Ledaña 'broad place' < *pl̥th2-ny-a.