In #OldIrish (well up into Classical Gaelic) relative clauses with āwhoseā relation (āthe man whose son is thereā type of thing) often didnāt contain any possessive pronoun.
Eg. the above ex. could be expressed in Classical Gaelic as āan fear fhuil mac ann sinā (or āā¦ a-tĆ” mac ann sinā). 2/n
McKenna in an appendix to āBardic Syntactical Tractsā notes more convoluted examples involving a prepositional pronoun, eg.:
crann ar a raibhe an t-Ć©an chraoibh āthe tree on whose branch the bird wasā
lit. ātree on which/whose was the bird branchā
craoibh ābranchā is in dative after āarā 3/n
And so exactly the same thing happens in those ā(an) duine is mĆ³ ciallā construction. It just directly continues the good old whose-relative clause, even though itās not felt as such anymore.
Historically it really just meant:
āthe person _whose_ sense is greatestā. 4/n
Today this would be expressed literally as:
(an) duine ar/gur mĆ³ a chiall
but the old way to phrase it with superlatives were apparently so common that the old way survived as a separate structure in the language. 5/n
In Classical Gaelic āas mhaithā and āas fhearrā show lenition cause relative āasā (āthat is, whose isā) caused lenition.
CrĆoch.
silmeth šŗš¦