In his 1707 book, Archaeologia Britanica, Edward Lhuyd noted the similarities between Welsh, Cornish, Breton, Irish Gaelic, and Scots Gaelic. He was the first to group them together under the generic term Celtic. He also pointed out that these languages belonged to two distinct sets which are distinguished by their pronunciation. He grouped Breton, Cornish, and Welsh as P-Celtic languages and Irish Gaelic and Scots Gaelic as Q-Celtic.
The origins of the word “Celtic” begins with ancient Greek in which “keltoi” was used as a derogatory catch-all name for strangers and foreigners. For the Romans, the terms “Celt” and “Gaul” were pretty much interchangeable and were used to describe the inhabitants of Roman territories in France and Northern Italy. It is interesting to note that in Roman- occupied Britain, the term “Celt” was not used in describing the native inhabitants. Yet, if we consider someone who speaks a Celtic language to be a Celt, then the occupants of Britain would have been Celts when the Romans invaded.
By 400 BCE, the Celtic languages were widely spoken in Europe, and particularly on the British Isles. During the Roman occupation of Britain, the Romans and the Celts often intermarried, and the two cultures often merged. After the Romans withdrew from Britain in 410 CE, the Celtic-speaking tribes predominated in Scotland, Wales, and Cornwall.
Despite their long association with Britain, the Celts had little impact on the development of the English language. Celtic influence is seen primarily in geographic place names, such as Avon, Dover, Kent, York, and Thames, rather than in everyday vocabulary. Even in vocabulary, the Celtic borrowings by English are often geographic.
Irish Gaelic: Modern English has about 40 words which were borrowed from Irish Gaelic, including: shamrock, leprechaun, galore, banshee, shillelagh, blarney, bother, keen, colleen. In Ireland, the majority of place names are from anglicized Gaelic. Thus the Gaelic “baile” (“homestead or settlement”) becomes the anglicized “bally” in Ballymena and “bealach” (pass or passage) becomes the anglicized “bally” in Ballyclare; “doire” (“grove or oak grove”) becomes “derry” in Derry (Londonderry); “cill” (“church”) become “kil” in Kildare; and so on.
Scots Gaelic: Modern English has about 30 words which were borrowed from Scots Gaelic, including: clan, plaid, cairn, bog, inch, whisky (from uisce beatha meaning “water of life.) The majority of place names in the Highlands of Scotland are from Scots Gaelic or from an anglicized Scots Gaelic.
Welsh: Modern English has about 10 words which were borrowed from Welsh, including: crag, penguin, gull. The majority of place names in Wales are from Welsh or from an anglicized Welsh.
While only a few Celtic words have been incorporated into English, there may be other influences. Linguists, such as Steven Laker and Peter Schrijver, have shown that there are signs of Celtic influence on English sounds. This influence on English phonology (the sounds used by a language) is seen in the formation of dialects, particularly in the northern regions.
With regard to the phonology of Irish English, P. W. Joyce, writing in 1910, points out:
“The Irish language has influenced our Irish-English speech in several ways. To begin with: it has determined the popular pronunciation, in certain combinations, of three English consonants, t, d, and th, but in a way (so far as t and d are concerned) that would not now be followed by anyone even moderately well educated.”
Joyce also notes:
“As for the English th, it may be said that the general run of the Irish people never sound it at all; for it is a very difficult sound to anyone excepting a born Englishman, and also excepting a small proportion of those born and reared on the east coast of Ireland.”
English today is, of course, one of the most frequently spoken languages in the world. There are today six “living” Celtic languages of which four have substantial numbers of native speakers: Irish Gaelic, Scots Gaelic, Welsh, and Breton. Two other Celtic languages—Cornish and Manx—have been undergoing revitalization movements. There are currently more than a million speakers of these Celtic languages.