Author's Note on the Story and Its Setting
Please be aware that while there are descendants of a Welsh culture addressed in later seasons of SG-1, this is one way in which my universe is alternative. This is a different Welsh group from the canon culture. The people of Tir Awyr were taken from the British Isles on Earth around the beginning of Roman occupation. They were spirited away and enslaved by a completely original Goa'uld posing as the deity Belatucadros no later than the 1st century CE, which is roughly four to five centuries prior to what might be considered "Arthurian" times. None of what I do in this story is intended to tie in with the canon Welsh arc in any way, because those events don't exist in my universe. Nor do the Ori.
Also, any modern or near-modern Welsh language used in this story is intended to stand in for a hypothetical related language, Pridanic, descended from the Brythonic language of the time when these people were taken from Earth. Brythonic was one of the two major language groups of the British Isles in pre-Saxon, pre-Roman times, and later went on to produce Welsh, Cornish, Cumbric, Breton and possibly other tongues. In the period from 100 BCE to ca. 150 CE, the time the Celtic peoples in this story were taken from Earth, Brythonic is postulated to have been one common language, possibly with two dialects. I am taking some license with the idea that another language evolved from Brythonic in off-world isolation would be at least close enough for a Welsh speaker to learn easily, although in actuality, that may not be as unlikely as it might sound, especially given the strong motivation of utter necessity. But in any case, if invoking artistic license is what it takes so that poor Frank can at least manage to communicate, then I'm all for it!
I will use a similar convention with regard to any other languages that crop up; if you, the reader, run across a Gaelic phrase in this work, it is intended to stand in for something evolved from a Goidelic language of the period spanning roughly 200 BCE to 200CE. Note that I am not a professional linguist (I only wish I could afford that much education!), nor do I play one on TV, and I'm just doing the best I can with online resources. I think I'm learning some of both Welsh and Scottish Gaelic in the process, so that's not a bad thing. Thank you for your understanding.