"He is demanding."
Translation:Tá sé ag éileamh.
I think there's some ambiguity here. In the English sentence, "demanding" looks like an adjective, but in the Irish it's a verb. It kind of begs the question of what is being demanded? Would this verb ever be used intransitively as it is here?
It is being used as a verb here, yes. It also doesn't look like there's an samples of it being used intransitively. My guess is they meant it as an adjective and used it as a verb. Here's a list of possible adjectival forms
So would "Is duine éilitheach é" do for "He is demanding" as in "He is (a) demanding (person)?
In the English sentence, “demanding” is a present participle, and in this sentence it could be interpreted either as part of a present progressive conjugation (e.g. “What is he doing? He is demanding.”, as an example of intransitive use) or as a predicative adjective (e.g. “What sort of man is he? He is demanding.”) As to what’s being demanded (the Irish sentence shows that the English participle should not be understood as an adjective), we don’t know, since it hasn’t been mentioned.
For me, when éiligh is used without an object it sounds more like complain so perhaps "He is complaining" would be a better translation here.
Actually, an intransitive sense of "to complain, or grumble", is cited in the entry for éiligh in Ó Dónaill.