Editing Openai/69186d20-2d14-8013-b9c6-c09000f173f6 (section)

=== Assistant: 2511141634ET ===
251114_1634ET

short answer: no, for ''Spáinn'' specifically there is no historical stage where its ''nn'' was both a true phonemic geminate and slender.

Longer, with timeline:

===== For “Spain” we have: =====
* Old Irish: Espáin (single n).
* Middle/early modern: Espáin / Spáin (still one n).
* Modern standard: Spáinn (with nn).

So:
* At the time of borrowing (Latin Hispānia → Old Irish Espáin), the word is written with a single n.
* The double nn is a later spelling development, not part of the original borrowing.

===== In Old Irish: =====
* There really were true geminate consonants; these are often written ll, mm, nn, rr.
* Over the Old Irish period, geminate consonants were shortened; by the end, the double spellings ll mm nn rr were repurposed to mark “fortis” sonorants (stronger / tense) rather than actual length.
* Palatalization (slender vs broad) is indicated by the adjacent vowels (e,i vs a,o,u), not by doubling itself.

Crucial: in the Old Irish form of this word, ''Espáin'', we don’t see that “fortis/geminate” spelling at all — just single n.

So even in Old Irish:
'' ''Espáin*’s final n is not written as geminate.
* Whatever its precise phonetic value there, it’s not one of the marked “nn” fortis/geminate sonorants.

===== Modern dictionaries and the Caighdeán give ''Spáinn'' with nn. =====

Given what we know:
* The nn in Spáinn is a modern orthographic regularization, influenced by: - general patterns like -ainn, -eann, -inn etc., and - a desire to mark a fortis/strong final nasal in line with other nouns.
'' By the time this spelling is standardized (20th c.), - true geminate length is long gone, - broad vs slender is already fully handled by the vowels, - so ''Spáinn* /ˈsˠpˠaːnʲ/ has a single slender /nʲ/ in actual pronunciation.

So synchronically:

: 

===== : =====

For this lexeme ''Spáinn'':
* At borrowing (Old Irish Espáin < Latin Hispānia): - No nn at all → therefore not geminate; slenderness is whatever the Espáin vowel environment implied, but it’s not marked by doubling.
* When nn appears in modern spelling: - the geminate contrast is already dead as a length distinction; - slender /nʲ/ is determined by the i, not by nn; - nn is orthographic / “fortis” only.

So: at no attested stage of this word’s life do we have “nn” simultaneously doing real geminate length and slenderness.

Geminate + slender did exist in the language historically (for other words), but not as an earlier phonetic stage of Spáinn; here the double n is a late spelling choice laid on top of a pre-existing slender n.