1. Q-Celtic languages:
- Scottish Gaelic (Gàidhlig): Spoken in parts of Scotland, primarily the Highlands and Western Isles.
- Irish Gaelic (Gaeilge): Spoken in Ireland and is the official language of the Republic of Ireland.
- Manx Gaelic (Gaelg): Spoken on the Isle of Man.
2. P-Celtic languages:
- Welsh (Cymraeg): Spoken in Wales.
- Breton (Brezhoneg): Spoken in Brittany, France.
- Cornish (Kernowek): Spoken in Cornwall, England.