Cai is the modern spelling,
Kai is the oldest spelling. Written Welsh hasn't used the letter K for about 400 years, but used to (there's a note on a probable reason why here:
http://en.wikipedia.org/wiki/Welsh_orthography).
The Welsh version of
Kevin is spelt '
Cefin' and pronounced exactly like
Kevin, as a single f in Welsh is pronounced like v in English. 'Keffyn' isn't a Welsh spelling as in Welsh it would be pronounced KEF-in, and, as I've said, Ks aren't used in modern Welsh except in foreign loan-words.
This message was edited 5/10/2010, 4:37 AM