There are six modern Celtic languages: Breton, Cornish, Welsh, Scottish Gaelic, Manx and Irish. They are classified as members of the Insular Celtic language family, and into two branches: the Goidelic languages (Irish, Manx and Scottish Gaelic), and the Brythonic languages (Breton, Cornish and Welsh).
Goidelic / Gaelic languages
Irish (Gaeilge)
Irish is spoken in mainly Ireland (Éire), and also in the UK (Ríocht Aontaithe), the USA (Stáit Aontaithe Mheiriceá), Canada (Ceanada) and Australia (an Astráil). 1.76 million people in Ireland claim to speak Irish, and about 186,000 of them speak it daily or weekly.
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Middle Irish (Gaoidhealg), was spoken from the 9th cenutry until about the 12th century.
More information about Middle Irish
Old Irish (Goídelc) was spoken in Ireland, the Isle of Man, Scotland and parts of western Britain between about the 6th and 9th centuries AD. Old Irish also developed into Manx and Scottish Gaelic.
More information about Old Irish
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Primitive or Archaic Irish is the form of Irish that appears in inscriptions in the ogham alphabet dating from the 4th to the 8th centuries AD. Such inscriptions have been found in Ireland, Wales, Scotland, the Isle of Man and England.
More information about Primitive/Archaic Irish
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Scottish Gaelic (Gàidhlig)
Scottish Gaelic is spoken mainly in Scotland, particularly in the Highlands and in the Western Isles. There are also a few thousand Gaelic speakers in Nova Scotia in Canada, mainly in Cape Breton Island and Prince Edward Island. About 60,000 people speak Gaelic, and another 26,000 have some knowledge of the language.
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Manx (Gaelg)
Manx is spoken on the Isle of Man (Ellan Vannin). Manx stopped being used as a community language in the early 20th century, although there were native speakers until the 1980s. It is being revived, and there are now about 1,800 people who have some knowledge of Manx, and a few hundred people who speak it fluently.
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More information about Goidelic languages
Brythonic / Brittonic languages
Breton (Brezhoneg)
Breton is spoken mainly in Brittany (Breizh) in the northwest of France by about 210,000 people. It is spoken mainly in western parts of Brittany, and also in parts of eastern Brittany, and by Breton immigrants in other parts of France, and in other countries.
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Old Breton (Brethonoc) was spoken between from 800-1100 AD, Middle Breton from about 1100-1650, and modern Breton thereafter.
More information about the history of Breton
Cornish (Kernewek)
Cornish is spoken mainly in Cornwall (Kernow) by about 3,000 people. It ceased to be used as a community language during the 18th century, although continued to be spoken during the 19th century, and was revived from the beginning of the 20th century.
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Old Cornish was spoken between from 800-1200 AD, Middle Cornish from about 1200-1600, and Late Cornish until the 19th century.
More information about the history of Cornish
Welsh (Cymraeg)
Welsh is spoken in Wales (Cymru) by about 740,000 people, and by several hundred people in the Welsh colony (yr Wladfa) in Patagonia, Argentina (yr Ariannin). There are also Welsh speakers in England (Lloegr), Scotland (yr Alban), Canada, the USA (yr Unol Daleithiau), Australia (Awstralia) and New Zealand (Seland Newydd).
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Middle Welsh (Kymraec), or Cymraeg Canol, is the form of Welsh spoken in Wales between the 12th and 15th centuries.
More information about Middle Welsh
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Old Welsh, or Hen Gymraeg, is the form of Welsh spoken in Wales from about 800 AD until the 12th century.
More information about Old Welsh
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Cumbric, a close relative of Old Welsh, was spoken in parts of northern England and southern Scotland until about the 12th century AD.
More information about Cumbric
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Pictish, which may have been a Brythonic language, was spoken in northern and eastern parts of Scotland until about 1100 AD.
More information about Pictish
Proto-Brythonic is the reconstructed ancestor of the Brythonic languages.
More information about Brythonic languages
More information about Insular Celtic languages
Continental Celtic languages
Continental Celtic languages, such as Gaulish, Celtiberian and Lepontic, were spoken in France, Spain and Italy, and other parts of continental Europe. Noric was possibly a Continental Celtic language, but is only know from two inscriptions dated to the 2nd century AD and found in Austria and Slovenia. Gaulish was spoken until about the 6th century AD, while other Continental Celtic languages disappeared before then.
Gallaecian was a Q-Celtic language or a group of languages spoken by the Gallaeci, Callaeci or Callaici, a federation of Celtic tribes who lived in what is now northern Portugal, and Galicia, western Asturias and western Castile and León in Spain. It is also known as Gallaic or Northwestern Hispano-Celtic. It appears as words and short sentences in Latin inscriptions, and in the works of classic authors; There are also quite a few place, river or mountain names of Gallaecian origin, and words were borrowed into the local Romance languages.
More information about Continental Celtic languages
Proto-Celtic is the reconstructed ancestors of all Celtic languages
More information about Proto-Celtic
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More information about Celtic languages
https://en.wikipedia.org/wiki/Celtic_languages
http://elalliance.org/languages/celtic/
Radio Omniglot podcasts about Celtic languages:
Scottish Gaelic, Irish, Manx, Welsh and Cornish.