<14304588851450819940726165849@comlab.ox.ac.uk> >The only exception I can think of to the rule for "un" as a numeral is >"blwydd" and "blynedd" which occur after "un" in instances like "un mlynedd >ar ddeg", "un mlynedd ar hugain" and so on, where it takes a different >mutation. The reason for this exception (as explained to me by one of my teachers) is that 'un' doesn't really mean 'one' in this context, but it's rather the 'one' in 'twenty-one' that happens to have gotten split up. >(Hah. And "blynedd" is of course a plural noun occurring here >after "un", contrary both to what you would expect about "un" and about >Welsh numerals in general.) 'blwyddyn' is exceptional in several respects. The normal plural is 'blynyddoedd', except with numerals, in which case you use 'blynedd' if you're counting years and 'blwydd (oed)' if you're counting ages. Plus, it has the nasal mutation after 'pump', 'saith', 'wyth', 'naw', 'deg', and so on, which as far as I know has been dropped from every other word except the occasional 'niwrnod'. Being so exceptional, I was going to introduce it (much) later... --Mark