Má tá an duine sin ann fós, níor bhuaileas leis riamh. Mar shampla, conas a déarfí "circle of the fifteen stones" as Gaelainn.

Ciorcal na gcúig gcloch ndéag
Ciorcal na gcúig gcloch déag
Ciorcal na gcúig chloch déag

Tá láithreach seandálaíoch i Músgraí agus tugtar "Ciorcal na gcúig gcloch" mar ainm air, ach chuala "na gcúig chloch" i gCiarraí. Cuirtear séimhiú tr'éis na n-uimhreacha ó trí go sé, ach is ainmfhocail iad na huimhreacha 3-6 agus dá bhrí sin cuireadh urú ina ndiaidh fadó (bhíodh "cloch" mar aidiacht tr'éis "cúig" agus ghlacadh an aidiacht an t-urú sa tuiseal ginideach iolra).

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The dialect I use is Cork Irish.
Ar sgáth a chéile a mhairid na daoine, lag agus láidir, uasal is íseal

According to Tobar na Gaedhilge (traditional Donegal literature), you use the urú after numbers in the genitive plural: after ceithre, cúig etc.
But according to several examples, "déag" isn't eclipsed in the genitive plural (in Donegal)

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Is fearr Gaeilg na Gaeltaċta ná Gaeilg ar biṫ eile
Agus is í Gaeilg Ġaoṫ Doḃair is binne

I though the lenition occurred if the noun ended with a vowel or a slender consonant, and that's all that affected the *deag*. Of course that could just be the Caighdeán.

No that is correct alright. If the noun is in the singular and ends with a vowel then déag is lenited. In Munster slender r tends to be included in any of these rules where you lenite after a vowel (aon uair dhéag), I didn't know it was all slender consonants in the Caighdeán.

Originally trí, cheithre, cúig and sé eclipsed in the genitive plural:

X na sé gcloch.

and in the genitive plural déag was originally eclipsed as well, such as in Céitinn:

i n-aois a shé mbliadhan ndéag

I have heard people say ndéag occasionally in Munster and you can see it in a few Munster books, such as:

Well I have nothing to add but more complications!

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The dialect I use is Cork Irish.
Ar sgáth a chéile a mhairid na daoine, lag agus láidir, uasal is íseal

Thanks for clearing that up, I thought for a minute I was beginning to get my head around it.

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Bíonn rudaí maithe mall

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