Sorry my questions never seem to come in ones!

Is 'i ndiaidh' a compound preposition? Does it treat following nouns like 'tar éis' would?

I saw 'i ndiaidh aifreann a hocht'in something and I had expected 'aifreann' to be in the genitive, as I thought that nouns that are qualified which follow after a compound preposition actually do go into genitive (unlike with verbal nouns), so what's 'i ndiaidh' up to here? :)

>Is 'i ndiaidh' a compound preposition?

yes since it has 2 words...

>Does it treat following nouns like 'tar éis' would?

yes.

Déarfainn gur ainmfhocal cinnte é an t-ainmfhocal "aifreann" agus é i dteannta le "a hocht" sa chás seo,

i ndiaidh aifreann a hocht

ach

i ndiaidh an aifrinn.

Sampla eile: hata an fhir / hata fhear an tí.

But I thought that after a compound preposition a noun that is qualified goes into the genitive?

It depends on what you want to say!

1. Tá mé i ndiaidh dinnéar a ithe.

ach

2. Caithim i ndiaidh éisc.

If the word is the object of i ndiaidh, then it is in the genitive (example 2). In the case of the tar éis/i ndiaidh being used as tense modifier (the "perfective"), then it does not. Usually it is followed by the verbal noun, or a word which is the object of a verbal noun (as shown in example 1). That tense denotes something which was completed in the immediate past. I usually think of it as "just" done.

I agree with Ormondo, Seánw and Lughaidh and I understand Sineadw's concern.

I don't know what the rules are but I would regard "Aifreann a hocht" as a unit, as if it were just one word, and as such "indeclinable".

The language is actually much easier than people who read the first few pages of a grammar think. Look for the "eisceachtaí." That difficult rule you are trying to learn may only apply rarely. As far as I remember there is a long list of occasions where "an tuiseal ainmneach" is used "in áit an ghinidigh."

There is another learner's rule which should be borne in mind: "If in doubt leave it out." Modern spoken Irish avoids the Tuiseal Ginideach if possible except for "na leaganacha seanbhunaithe."

If the choice is between on the one hand not using Irish because you are unsure of the grammar and on the other taking the easy option of leaving out the difficult changes that you are unsure of and that don't seem to fit or sound well I suggest you should follow the latter course. You won't be mistaken for a native speaker of Irish. But you won't be taken for a Béarlóir either and your attempts to speak Irish will be appreciated. The pursuit of perfection (unattainable) will actually spoil your Irish and make it impossible for you to avoid switching to English at every hurdle.

Once you get into the habit of speaking Irish you will hear the correct forms and they will be pointed out to you.

Writing Irish is a different matter of course. There you have time to think and refer to the dictionary and the grammar etc.

Thanks all, I was hoping for a rule that would help me I guess! But I've looked through the other examples, here and elsewhere, and I finally have grasped it. Cheers.

"If in doubt leave it out"

My old teacher of Irish had another sentence "when in doubt, find out!" -- you're more likely to improve your Irish by following his motto, rather than by following the other one... :-)

Unfortunately, speaking Irish "on the hoof" one is unlikely to be able to raise one index finger to alert your hearer that you have more to say and with the other hand riffle through Ó Dónaill, Dinneen, An Caighdeán Oifigiúil, Cora Cainte as Tír Chonaill, Caint an Chláir, Caint an tSean-Shaoghail Vols 1 & 2, agus Peig leis an leagan ceart a dheimhniú. You could add Gnás na Gaeilge or anything by Cormac Ó Cadhla to that list.

On the other hand, if you are being interviewed on RTÉ RnaG you don't have much choice so "when in doubt (about some tortuous grammatical change that you don't really know and doesn't come easily to you take a chance and) leave it out." Not all your listeners will have a PhD in The Incidences of Irish Grammar Variations from The Kyedawn in Baile i bhFad Siar. [Please don't take offence anyone. I'm joking. D'aonghnó atáim. Horseman, smile and pass on.)

"If in doubt leave it out"	agus tú ag caint
"when in doubt find out!"	nuair atá tú ag léamh/scríobh nó tar éis duit bheith ag caint

Comhairle fiúntach san dá chás.

Go direach, a Aonghus.

´hata an fhir / hata fhear an tí.

Cén fáth an séimhiú?

GRMA

"Suspended genitive" a bheirtear air sin.

Tuigim cad tá i gceist, ach an mbíonn séimhiú ann i gcónai sa chás so?