512. This peculiar construction has arisen from the fact that these numerals are really nouns, and formerly governed the nouns after them in the genitive plural. As the genitive plural of most Irish nouns has exactly the same form as the nominative singular, the singular form has come to be almost universally used in Modern Irish after these numerals. Formerly they would use ceud ban and fiċe caoraċ, but now we use ceud bean and fiċe caora.
513. The word ceann and its plural cinn are often used with numerals when the noun is not expressed in English: as, Ca ṁeud (an’mó) leaḃar agat? Tá ḋá ċeann deug agam. How many books have you? I have twelve.
- Tá ceann (or duine) aca ins an tiġ.
- There is one of them in the house.
The Dual Number.
514. Ḋá, “two,” always takes the noun after it in the dual number (neither singular nor plural), which in every Irish noun has the same form as the dative singular. This does not at all imply that the noun after dá is in the dative case. It is in the dative singular form, but it may be in any of the five cases, according to its use in the sentence. All the cases of the dual number are alike, but the form of the genitive plural is often used for the genitive dual: ḋá ḃuin, two cows; ḋá ġaḃainn, two smiths; lán a ḋá láiṁ or lán a ḋá láṁ, the full of his two hands.
