I would assume it to be “Kotch-leen” if I were in Ireland or at a Ceili, and “Kate-linn” if I were in a more American setting.
I’m really surprised at some of the Irish answers below. Although I understand the shared roots, it would never occur to me to pronounce it “Kath-leen” if it’s spelled with a c-a-i-t. Do people really do that?
Closest is Kathleen, as others have explained the lack of a direct translation to English. I still think of the Kate Lynn way as being a sign that people didn’t know any better, but I also realize the tide has turned and I’m just being pedantic about it. (And I say that as someone who has a relative whose name is pronounced “dee-dray” because her mother read it in a book.)
We had a similar issue in our household when my husband decided he wanted to name our daughter Caitriona, only he believed it was okay to pronounce it however he liked. I used the veto.
^And this. I was going to post about the fada if no one else had. The name just isn’t proper Irish unless the fada is included, and without it, the key to Irish pronunciation of the name is lost. I voted for number 4; I’m not from Ireland, but my ancestors are, and I’ve studied the language some.
To understand Irish phonology you have to learn to distinguish “lean” consonants from “broad” ones. The “lean” (i.e. palatalized) ones are adjacent to the letters e and i. Often the e or i isn’t pronounced but it’s there to show that the consonant next to it is palatalized. The “broad” consonants are adjacent to a, o, or u. Again, they may not be pronounced but rather put there to show that the consonant isn’t palatalized. It’s slightly more complex than that, but that’s the basic principle.
The fada (acute accent) on vowels is important because any vowel marked with it is long and is always pronounced. The unaccented vowels adjacent to the long vowel with fada are not pronounced but affect the consonants next to them.
For earlier generations of Irish-Americans like the Kennedys the approximate phonetic spelling of Kathleen was good enough and at least not terribly far off for English speakers who completely lack the lean/broad distinction. But then we got our Celtic pride up and would settle for nothing less than the authentic original Irish name, so everybody became Caitlin—except that without the fada, and with a pronunciation completely unlike the Irish original, I would say the whole point of trying to be “authentically” Gaelic was lost. On FAILblog.org, this would be noted as “Irish FAIL.”
I mean if you’re introduced to someone and her name is Kathleen and you want to write a mash note to her later, how do you decide which spelling to use (Caitlin or Kathleen)?
If I saw ‘Caitlin’, I’d pronounce it ‘Katelyn’. If I saw ‘Cáitlín’, I’d pronounce it ‘Kawtchleen’ (roughly). I wouldn’t pronounce it ‘Kathleen’ either way, but that’s one of those things that can vary regionally, and I’m pretty sure An Gadaí and I are from different bits of Ireland.