And also, perchance, usable in the more literal sense?
"How long does he have to achieve his life's goals? He has eighty years"
I wondered if it would be just for age, but erred on the side of literalism, as I had an idea age might have been "eighty years are at/upon/with him" or such.
It could be in that context, though something like Tá seal ochtó bliain aige (“He has a span of eighty years”) might also be said as a reply.
Why not "Tá ochtó bliana aige"?
Quoting Duolingo's Tips and notes:
"An exception applies for nine particular nouns: they use a plural form instead of the singular form when they are counted with bunuimhreacha. They are:
You don't use it except after 3-10, and when those numbers are used in higher counting.
If you were to say 85, though, you'd still use it Tá cúig bliana is ochtó aige.
The exception that applies to these nouns that are pluralized after numbers also exempts them from lenition after 3-6 (but not eclipsis after 7-10), so cúig bliana, sé bliana, seacht mbliana.
It's like Spanish, then, in expressing age as a number of years possessed.
He's eighty years wasn't accepted but he is eighty years was??? Its pratically the same answer!!!!
He is eighty years ----not accepted but I'm advised by DL that "he's eighty years" is acceptable. Slightly confused!
The literal translation is that he has, not is, eighty years; perhaps he's is viewed as an abbreviation of he has. To use is you need to go all the way to how one says the meaning in English, he is eighty years old