The Insular Celtic hypothesis concerns the origin of the Celtic languages. The six Celtic languages of modern times can be divided into: NB *See note on Irish Governments perception of the term British Isles directly below. ... Current distribution of Human Language Families Most languages are known to belong to language families. ... The Indo-European languages comprise a family of several hundred languages and dialects [1], including most of the major languages of Europe, as well as many in Southwest Asia, Central Asia and South Asia. ... The Celtic languages are the languages descended from Proto-Celtic, or Common Celtic, spoken by ancient and modern Celts alike. ... The Brythonic languages (or Brittonic languages) form one of the two branches of the Insular Celtic language family. ... The Goidelic languages (also sometimes called the Gaelic languages or collectively Gaelic) are one of two major divisions of modern-day Insular Celtic languages (the other being the Brythonic languages). ... The Celtic languages are the languages descended from Proto-Celtic, or Common Celtic, spoken by ancient and modern Celts alike. ...

• the Goidelic languages (Irish, Manx, and Scottish); and
• the Brythonic languages (Breton, Cornish and Welsh).

The term "Insular" refers to the place of origin of these languages, the British Isles, in contrast to the (now extinct) Continental Celtic languages of mainland Europe and Anatolia. There is a theory that the Brythonic and Goidelic languages evolved together in those islands, having a common ancestor more recent than any shared with the Continental Celtic languages such as Celtiberian, Gaulish, Galatian and Lepontic, among others, all of which are long extinct. Goidelic is one of two major divisions of modern-day Celtic languages (the other being Brythonic). ... Scottish Gaelic (Gàidhlig) is a member of the Goidelic branch of Celtic languages. ... Brythonic is one of two major divisions of Insular Celtic languages (the other being Goidelic). ... Breton (Breton: Brezhoneg) is a Celtic language spoken by some of the inhabitants of Brittany (Breizh) and Loire-Atlantique (historically part of Brittany) in France. ... This article or section does not cite its references or sources. ... Welsh redirects here, and this article describes the Welsh language. ... NB *See note on Irish Governments perception of the term British Isles directly below. ... The Continental Celtic languages are those Celtic languages that are neither Goidelic nor Brythonic. ... Continental Europe, also referred to as mainland Europe or simply the Continent, is the continent of Europe, explicitly excluding European islands and peninsulae. ... Anatolia lies east of the Bosphorus, between the Black Sea and the Mediterranean Anatolia (or Anatolian Peninsula) is a region of Southwest Asia which corresponds today to the Asiatic portion of Turkey, as opposed to the European portion, the Thrace. ... Historical linguistics (also diachronic linguistics or comparative linguistics) is primarily the study of the ways in which languages change over time. ... Missing link is a term for a transitional form from the fossil record that connects an earlier species to a later one, or which connects two different species to an earlier ancestor. ... The Continental Celtic languages are those Celtic languages that are neither Goidelic nor Brythonic. ... Celtiberian (also Hispano-Celtic) is an extinct Celtic language spoken by the Celtiberians in northern Spain before and during the Roman Empire. ... Gaulish is the name given to the Celtic language that was spoken in Gaul before the Vulgar Latin of the late Roman Empire became dominant in Roman Gaul. ... Lepontic is an extinct Celtic language that was once spoken in Northern Italy between 700 BCE and 400 BCE. The language is only known from a few inscriptions discovered that were written in a variety of the Northern Italic alphabet, which was related to the Old Italic alphabet. ... In biology and ecology, extinction is the ceasing of existence of a species or group of species. ...

The proponents of the Insular Celtic hypothesis point to shared innovations among Insular Celtic languages, including inflected prepositions, shared use of certain verbal particles and VSO word order. They assert that a partition that lumps the Brythonic languages and Gaulish (P-Celtic) on one side and the Goidelic languages with Celtiberian (Q-Celtic) on the other may be a superficial one (i.e. owing to a language contact phenomenon), as the identical sound shift (Q to P) could have occurred independently in the predecessors of Gaulish and Brythonic. In grammar, inflection or inflexion is the modification or marking of a word (or more precisely lexeme) to reflect grammatical (that is, relational) information, such as gender, tense, number or person. ... Verb Subject Object—commonly used in its abbreviated form VSO—is a term in linguistic typology. ... Brythonic is one of two major divisions of Insular Celtic languages (the other being Goidelic). ... Goidelic is one of two major divisions of modern-day Celtic languages (the other being Brythonic). ... Language contact occurs when speakers of distinct speech varieties interact. ...

The family tree of the Insular Celtic languages is thus as follows:

• Insular Celtic
  • Goidelic
    • Primitive Irish, ancestral to:
      • Old Irish, ancestral to:
        • Middle Irish, ancestral to:
          • Irish
          • Scottish Gaelic
          • Manx
          • Galwegian
  • Brythonic
    • Cumbric
    • Pictish (possibly)
    • Old Welsh, ancestral to
      • Middle Welsh, ancestral to:
        • Welsh
    • Southwestern Brythonic, ancestral to:
      • Breton
      • Cornish

The Goidelic languages (also sometimes called the Gaelic languages or collectively Gaelic) are one of two major divisions of modern-day Insular Celtic languages (the other being the Brythonic languages). ... Primitive Irish is the oldest known form of the Irish language, known only from fragments, mostly personal names, inscribed on stone in the Ogham alphabet in Ireland and western Britain up to about the 6th century. ... Old Irish is the name given to the oldest form of the Irish language which can be, more or less, fully reconstructed from extant sources. ... Middle Irish is the name given by historical philologists to the form of the Irish language from the 10th to 16th centuries; it is therefore a contemporary of Middle English. ... Scottish Gaelic (Gàidhlig) is a member of the Goidelic branch of Celtic languages. ... Galwegian Gaelic is an extinct Goidelic dialect formerly spoken in South West Scotland. ... The Brythonic languages (or Brittonic languages) form one of the two branches of the Insular Celtic language family. ... Cumbric was the Brythonic Celtic language spoken in Cumbria, and the southern Lowland Scotland . ... A replica of the Hilton of Cadboll Stone. ... Old Welsh (Hen Gymraeg) is the label attached to the Welsh language from the time it developed from the Brythonic language, generally thought to be in the period between the middle of the 6th century and the middle of the 7th century, until the early 12th century when it developed... Middle Welsh (Cymraeg Canol) is the label attached to the Welsh language of the 12th to 14th centuries, of which much more remains than for any earlier period. ... Welsh redirects here, and this article describes the Welsh language. ... Southwestern Brythonic is one of two dialects into which the Brythonic language split following the Battle of Deorham in 577 CE; the other being Western Brythonic, which later evolved into Welsh and Cumbric. ... Breton (Breton: Brezhoneg) is a Celtic language spoken by some of the inhabitants of Brittany (Breizh) and Loire-Atlantique (historically part of Brittany) in France. ... This article or section does not cite its references or sources. ...

References