The word Celt today is most usually applied to a Briton or a Gaul. Celt also can refer to a speaker of a modern Celtic language or to a speaker’s descendants, or so says the American Heritage Dictionary, third Ed.
The Celtic languages are a group of languages in the Indo-European family. The Germanic group, which contains Norse, Swedish, Dutch, German and English, is another branch of the Indo-European family tree, while the Romance group, (now often called Italic) which includes the languages Latin, Portuguese, Spanish, French, Italian French, and Romanian, is a third branch of the I.E. tree.
The Celts are an Indo-European people who spread from central Europe across the European continent to western Europe, the British Isles, and southeast to Galatia (in Asia Minor) during the time before the Roman empire. The Celtic family of languages is divided into two branches, the Insular Celtic languages, and the Continental Celtic languages. The Continental branch includes the languages Gaulish, Celtiberian, and Lepontic. These were languages spoken on the European continent. There are no living native speakers left today; they all died over a thousand years ago. But we do have lots of inscriptions, on stone, wood, and especially, metal plates. Scholars have used their knowledge of the other Celtic languages, and of Greek and Latin, in order to make very educated guesses about inscriptions. And sometimes the same inscription is presented in Latin or Greek as well as in one of the Continental Celtic languages. We now know quite a bit about the various Continental languages, and are learning more as more inscriptions are discovered, transcribed, deciphered and translated.
The Insular Celtic languages are mostly those spoken on the islands of Britain, Ireland, Man, and part of France. The Insular languages belong to one of two branches, the Goidelic and the Brythonic. The Goidelic languages are Irish Gaelic, Scottish Gaelic, and Manx. Manx is a form of Gaelic spoken on the Isle of Man. The last native speaker of Manx died in 1974, but many are learning the language today, and we have recordings of native speakers. Irish and Scottish Gaelic are both still used by native speakers. In addition to living native speakers in Ireland and Scotland, there are also native Scottish Gaelic speakers in Nova Scotia, Canada. We also have many medieval Irish manuscripts, containing Ireland’s national epic the Táin Bó Cuailnge and other Irish myths, poetry and lore, and a few medieval Scottish Gaelic mss.
The Brythonic languages form the other branch of the Insular Celtic languages. Welsh, Cornish, and Breton are Brythonic. There are still many native speakers of Welsh today, mostly in Wales. The last native speaker of Cornish died in the late eighteenth century, but there are a number of people in Cornwall and elsewhere who have attempted to learn Cornish and even rejuvenate the language. Breton is spoken in Bretagne, or Brittany, in France, by descendants of British Celts who moved there over a thousand years ago. We have fewer medieval Welsh manuscripts preserving the mabinogi and other traditional Welsh tales, poetry and lore, than we have of Irish, but Welsh literature is alive and well.
The Goidelic languages are often referred to as “Q-Celtic” because they use a “Q” sound, usually represented by a C or K, where the Brythonic or “P-Celtic” languages use P. For instance, Irish and Scottish Gaelic for “head” is ceann, or sometimes kin. Brythonic languages, P-Celtic Welsh and Cornish, use pen. There’s a place on the coast of Cornwall called Pentire, and one on the coast of Scotland called Kintyre. Both mean “head of the land.” There are hundreds of similar P and C initial words that indicate the relationship between P-Celtic and Q-Celtic languages. In Celtic linguistics, it really pays to “mind your Ps and Qs.”