Celtiberian is an extinct

Extinct language

An extinct language is a language that no longer has any speakers., or that is no longer in current use. Extinct languages are sometimes contrasted with dead languages, which are still known and used in special contexts in written form, but not as ordinary spoken languages for everyday communication...

 Indo-European

Indo-European

Indo-European may refer to:* Indo-European languages** Aryan race, a 19th century and early 20th century term for those peoples who are the native speakers of Indo-European languages...

 language of the Celtic

Celtic languages

The Celtic languages are descended from Proto-Celtic, or "Common Celtic"; a branch of the greater Indo-European language family...

 branch spoken by the Celtiberians

Celtiberians

The Celtiberians were Celtic-speaking people of the Iberian Peninsula in the final centuries BC. The group used the Celtic Celtiberian language.Archaeologically, the Celtiberians participated in the Hallstatt culture in what is now north-central Spain...

 in an area of the Iberian Peninsula lying
between the headwaters of the Duero, Tajo, Júcar

Júcar

The Júcar or Xúquer is a river on the Iberian Peninsula of Spain. The river runs for approximately 509 km from its source at Ojuelos de Valdeminguete, on the eastern flank of the Montes Universales, Sistema Ibérico...

 and Turia

Turia

Turia can refer to:*Turia , a river in southeastern Spain*Turía , a small river in northern Spain*Turía , a small Web development company in india*Turia Valley, a valley in northern Spain...

 rivers and the Ebro

Ebro

The Ebro or Ebre is one of the most important rivers in the Iberian Peninsula. It is the biggest river by discharge volume in Spain.The Ebro flows through the following cities:*Reinosa in Cantabria.*Miranda de Ebro in Castile and León....

 river. This language is directly attested in nearly two hundred inscriptions dated in the 2nd century BC and the 1st century BC, mainly in Celtiberian script

Celtiberian script

The Celtiberian script is a paleohispanic script that was the main means of written expression of the Celtiberian language, an extinct Continental Celtic language, also expressed in Latin alphabet...

, a direct adaptation of the northeastern Iberian script

Northeastern Iberian script

The northeastern Iberian script is also known as Levantine Iberian or Iberian, because it is the Iberian script that was most frequently used, and was the main means of written expression of the Iberian language. The language is also expressed by the southeastern Iberian script and by the...

, but also in Latin alphabet

Latin alphabet

The Latin alphabet, also called the Roman alphabet, is the most recognized alphabet used in the world today. It evolved from a western variety of the Greek alphabet called the Cumaean alphabet, which was adopted and modified by the Etruscans who ruled early Rome...

. The longest extant Celtiberian inscriptions are those on three Botorrita plaque

Botorrita plaque

The Botorrita plaques are four bronze plaques discovered in Botorrita , near Zaragoza, Spain, dating to the early 1st century BC, known as Botorrita I, II, III and IV....

s, bronze

Bronze

Bronze is a metal alloy consisting primarily of copper, usually with tin as the main additive. It is hard and brittle, and it was particularly significant in antiquity, so much so that the Bronze Age was named after the metal...

 plaques from Botorrita

Botorrita

Botorrita is a municipality located in the province of Zaragoza, Aragon, Spain.Botorrita is known for the archeological artefacts found there, such as the Botorrita plaques....

 near Zaragoza

Zaragoza

Zaragoza , also called Saragossa in English, is the capital city of the Zaragoza Province and of the autonomous community of Aragon, Spain...

, dating to the early 1st century BC, labelled Botorrita I, III and IV (Botorrita II is in the Latin language

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

).
Celtiberian was a Celtic language that shows the characteristic sound changes that define Celtic languages such as:

• loss of Proto-Indo-European
  Proto-Indo-European language
  The Proto-Indo-European language is the reconstructed common ancestor of the Indo-European languages, spoken by the Proto-Indo-Europeans...
  
   (PIE) voiced aspiration, e.g.