Counting Down

Numbers come in a couple of different flavors. There are the cardinal, or counting numbers (1, 2, 3, 4...) and the ordinal numbers (first, second, third...) in English, and Irish ads a third form of the numbers that are used specifically for counting people (aon, beirt, tríur, etc).

Cardinal numbers are used to 'say' numbers, and to count things.

No.	Cardinal Numbers
1	a haon	20	a fiche
2	a dó	30	a tríocha
3	a trí	40	a ceathracha
4	a ceathair	50	a caoga/a leathchéad
5	a cúig	60	a seasca
6	a sé	70	a seachtó
7	a seacht	80	a hochtó
8	a hocht	90	a nócha
9	a naoi
10	a deich	100	céad
11	a haon déag	200	dhá chéad
12	a dó dhéag	300	trí chéad
13	a trí déag
14	a ceathair déag	1000	míle
15	a cúig déag
16	a sé déag	21	fiche a haon
17	a seacht déag	22	fiche a dó
18	a hocht déag
19	a naoi déag	101	céad a haon
		102	céad a dó

The particle 'a' in front of the numbers is usually omitted (except when actually 'spelling something out' in numbers or counting aloud). Saying serial number out loud, for example, would be 15368, "a haon, a cúig, a trí, a sé, a hocht".

Counting things does require a few changes - the words for one, two, and four change form slightly when you count things --

a haon (one), but teanga amháin (one language)
a dó (two), but dhá theanga (two languages)
a ceathair (four), but ceathre theanga (four languages)

You'll notice a couple of things about those statements though - when you count stuff, you only need to know the singular noun for it -- trí teanga (three languages), although teangacha (languages). That's pretty convenient for us beginners! I know quite a few nouns, but I don't yet know all their forms.

Also, the numbers 2-6 aspirate the following noun according to the standard rules. The numbers 7 -10 eclipse the noun.

Perhaps the biggest change for English speakers is that when you count more than ten things, the name of the thing being counted goes between the number and the tens. Instead of staying 'fifteen languages' you says something like 'five languages and ten'.

cúig phunt--> five pounds,
but cúig phunt déag --> fifteen pounds
seacht bpunt --> seven pounsd,
but seacht bpunt déag --> seventeen pounds

Over twenty, and there are two ways to express it: either as 'thirty and five pounds' or 'five and thirty pounds'. Notice the words 'is a' in the middle - in this case 'is' is an abbreviation for 'agus' (and) and the 'a' is the counting particle shown above. Then tend to disappear when you actually say the words, at least they do in my various audio files.

tríocha is a cúig phunt --> thirty-and-five, or
cúig phunt is tríocha --> five-and-thirty

Or, if you want to be a bit more archaic about it, some references still suggest counting by twenties, so thirty is actually 'twenty and ten' -- you'll see 'fichid' often in older books. For example, 33 could be 'trí teanga déag is fiche" -- literally, thirteen-and-twenty, or 60 expressed as 'trí fichid'. p. 131-2 of Learning Irish uses this method of counting, although TY Irish and Irish on your Own use the versions shown above - seasca is 60, etc. I am not honestly sure if this is a regional difference, or simply a reflection of the new standard in many of the newer class texts. From what I can tell, either form is correct - seasca or trí fichid. I have heard the non-decimal version on the radio at least once.

If I recall correctly, French has the same construct for seventy, eighty, and ninety - seventy is literally -sixty-ten, or soixante-dix. Nothing like doing an extra bit of math! Expressin a a number as seventeen and four twenties (97) seems awkward to me, but I suppose it's entirely natural if you were taught that way.

Counting people is a bit different --Irish has special words for counting people (duine amháin, beirt, tríur, ceathrar, cúigear, seisea, seachtar,ochtar, naonúr, deichniúr). I have two sons --> tá beirt mhac agam, for example. The numbers 1-10 and the number 12 exists for counting people, otherwise the regular cardinal numbers are used. Twelve is dháréag.

The rule seems to be that this form of the word is only used for people, not for counting living things, etc. I'm sure I'm completely wrong in saying that I have two dogs using 'beirt mhadra' even though I think of them as family members. I'm one of those people who refers to my dogs as he and she, not it. (And not my kids, either, I'm not quite that weird!)

More than you ever wanted ot know about numbers in Irish, from Gramadach na Gaeilge

And someone has actually put together the numbers 1-10 in over 500 languages!