I seem to be seeing compund words and genitve compounds that are not so clear in how to do them. Would these be the rules below? I know some examples are odd...

cos (f) =foot cat (m) =cat gabhar (m) =goat cleiteog (f) =wing

The matrix will be then:

Compound (C): f,f f,m m,f m,m
Rule: stick together and glue by lenition with second (spot join/weld them). Second noun acts like an adjective.

Genitive (G): f,f f,m m,f m,m
Rule: when second is feminine render into case (melt) and just place noun side by side; when second masculine render to case and also join by lenition.

Examples: (* =main noun word of phrase)

cos (f) =foot cat (m) =cat gabhar (m) =goat cleiteog (f) =wing

Compound (C): f,f (2) f,m m,f m,m

foot-wing* = cleiteog-chos
wing-*foot = cos-chleiteog

foot-goat* = gabhar-chos
goat-foot* = cos-ghabhar

goat-cat* = cat-ghabhar
cat-goat* = gabhar-chat

crúb (f) =claw cat (m) =cat gabhar (m) =goat súil (f) =eye

Genitive (G): f,f (2) f,m m,f m,m

claw of an eye* = crúb-súla
eye of a claw* = suil-crúibe

claw of a cat* = crúb-chait
cat of a claw* = cat-crúibe

goat of a cat* = gabhar-chait
cat of a goat* = cat-ghabhair

Hmmm. Your examples are distracting me a bit (perhaps because I'm trying to attach meaning to them as words.) How about some more ordinary ones?

anamchara (m-m) - confessor (= "soul friend")
bláthfhleasc (m-f) - garland (= "flower loop")
réaltbhuíon (f-f) - constellation (= "star troop")
lámhchleasaí (f-m) - juggler (= "hand trickster")

The first component (anam, bláth, réalt, lámh) is the one that "acts like an adjective." Gender and declension are taken from the second component. Hyphens are only used to separate identical consonants, e.g.
lámh-mhaisiú - manicure (= "hand adornment")


For the genitive, there are two possibilities. The qualifying noun can be used attributively (i.e. as an adjective) or as a noun in apposition:
gloine beorach - a beer glass (appositive)
gloine bheorach - a glass of beer (attributive)


Appositive genitives are never lenited.

Attributive genitives are treated just like attributive adjectives (i.e. lenited after feminine nouns or plurals ending on slender consonants) with the exception that the DeNTaLS rule does apply (it doesn't for attributive adjectives):
an bhean dheireanach (attributive adjective)
an bhean deiridh (attributive genitive)


Of course you only see a difference between the two if the first noun is feminine or a weak plural (and the second one starts with a consonant that admits lenition), and there's not always (or even usually) a significant difference of meaning - a nead circe is pretty much always a nead chirce and vice versa! But it's still a worthwhile distinction and I do wish grammar books would stress it just a bit more.

Thanks, Abigail. I'm going to digest this and might post something more

Here's how you put nouns together in Irish:

[main word] [less important word] [less imporant word]

Therefore:

schoolbag = mála scoile
sunlight = solas gréine

To break it down grammatically:
1) The main word is unchanged
2) The less important word assumes its genitive case.
3) Initial-consonant mutations occur to the less imporant word depending on the gender and case of the main word.

There is another far less common way of doing it:

[less important word] [main word]

People have to be careful when they make up terms of this kind, as it can lead to confusion as it's the mirror image of the above method. When it is used however, the first noun has one syllable:

chequebook = seicleabhar

This method tends to be only used with very recognisable terms, and it would amount to roughly 1% of compound terms in Irish. Really, you don't have to learn about it, and you shouldn't be using it yourself -- all you should do is learn the ones that use it.