So the basic form of a verbal noun sentence is:
Táim ag déanamh na mbróg
If you choose to emphasise the shoes by fronting them you would get:
Is iad na bróga atáim a dhéanamh
Why "a dhéanamh"? In modern Irish there is no explanation, it is simply a rule of its own. If the object of a verbal noun preceeds the verbal noun in another clause you use "a + verbal noun", not "ag + verbal noun"
There was a reason in Classical Irish, but that would take us a bit away from the issue.
Now, what remaining questions do you have?
Also you are not struggling with a basic sentence, rather you are breaking into intermediate level where Irish grammar really ramps up. There are things about the verbal noun and copula that no modern books outside of academic texts deal with, so it will be hard.
EDIT: To be honest I have thought of making a study group where I select sentences and paragraphs from older texts and explain them. Sentences choosen for their difficulty and encapsulation of finer grammatical points. Would anybody be interested?
Since I am on my mobile app at the moment I can not see either the names or the dates when your comments were posted. I would really appreciate a group which helps me to get a better understanding of the sentences and the grammar. If it already exists, where can I find it on the website? I am fairly new to all things related to a computer and sometimes I don't even know where to look for resources. (But I am getting there ;-))
In essence it is the é in "Cad é" that functions as the object.
For anybody interested the "a rá" is related to the distiction between "do rá" and "ag rá" that existed in Classical Irish, e.g. do do bhualadh vs ag do bhualadh
Does anybody know a good venue for a study group online? I could start this weekend.
There are two Duolingo Irish groups on Facebook (that I know of - perhaps there are more.).
The links below should work, but then you will need to log into Facebook. For both, you need to request to join, but the responses are fast.
One is run by Niamh and the other, I think, by Alexinireland.
Here they are: https://www.facebook.com/groups/duolingo.gaeilge/?fref=ts
Is this type of construction more common in Irish than it is in English, or is this just a way of teaching it to us? I think it's really unlikely a person would say it that way in English because it's really awkward. It doesn't necessarily follow that it's awkward in Irish though so, just wonderin'!
Cad 'tá á rá agat is a good example of where the passive is more common. Cad é an rud atánn tú a rá, the active form, is much rarer.
If you think about it, in a passive sentence, the emphasis is on the logical object, and in "What are you saying", the emphasis is on "the thing you are saying", which is the logical object. So it is natural that they go together.
Thank you, that's very helpful. But I'm still confused about the construction for the original sentence. I've looked on some of the forums, and there are a lot of conflicting opinions about the construction that should be used. Could you please help me understand how this sentence works, preferably in the Ulster dialect? I honestly feel like giving up if I can't understand how to put together such a seemingly basic sentence after over a year of study.
The thing that is bending my brain is that "tá ... agat" expresses the possessive "you have ...". It led me to render it "what is it that you have said" which begs someone to make the same clarification as the idiomatic "What are you saying?". Moreover, either question would clearly come about AFTER the not-understood thing had been said rather than concurrent with the speakers actually saying it. Unless of course the questioner is intentionally rude while the other is still speaking. Could it be that we have an English idiomatic trying to be bent into fitting perfectly understandable Irish when they are merely equivalent meanings?
"have you anything to say?" - an bhfuil aon rud le rá agat?
"what have you got to say for yourself?" - cad atá le rá agat duit féin?
"Do you have anything else to say?'" - An bhfuil aon ní eile le rá agat?
"what did he have to say about that?" - céard a bhí le rá aige faoi sin?