The Welsh language is the primary Celtic language. Spoken Welsh frequently uses the k, but the Welsh alphabet does not have a k and there is a story behind that fact.

Up until the sixteenth century Welsh words with the k sound were spelled with a k. But in 1567 William Salesbury published his translation of the New Testament of the Bible into Welsh. In that translation all of the k sounds were represented by s. This was his type-setters told him that they did not have enough ks so he told them to use cs instead.

Salesbury's translations became the norm for written Welsh and soon k disappeared in written Welsh. Unfortunately this meant that English speakers misapprehend Welsh words. For example the word the Welsh use for themselves is Cymræg, which is pronounced as though it were spelled as Kymry.

The word celt has an interesting history. Originally it meant an oblong stone piece used in a battle hammer. When archeologists dug up these stone pieces some of them discovered by pure chance that a celt has a strange property. When a celt is spun on a horizontal surface it spins for awhile and then rattles to a stop and starts spinning in the opposite direction. This has to be seen to be believed. The archeologist who discover this property of a celt must have thought it was haunted. Physicists explain this phenomenon in terms of an asymmetry in the shape of the celt