> 'Amin, a Chonaill!' ar Cet. 'Cid sin, a Ceit?' ar Conall.
I think amin is the word at DIL A 304.8, whose meaning 'thus' etc doesn't
seem to work here - does DIL's 'often as mere expletive' perhaps apply?
Cid looks like ce with 3rd singular subjunctive copula.
My attempt is:
'Hey, Conal!' said Cet. 'What is it, Cet?' said Conall.