-aí

• IPA^(key): /iː/

From earlier -aidhe, originally the Old Irish accusative and vocative plural ending of d-stem nouns. For example Old Irish arae, plural arada.

• -aidhe (obsolete)
• -í (slender form)
• -idhe (obsolete slender form)

-aí

1. Ending of the plural of certain nouns.

   ‎beannacht (“blessing, greeting”) + ‎-aí → ‎beannachtaí

   ‎gnólacht (“commercial firm”) + ‎-aí → ‎gnólachtaí

A merger of two different Old Irish suffixes. One the one hand, from Old Irish -id, from Proto-Celtic *-yatis, an extended variant of Proto-Celtic *-atis. On the other hand, from Old Irish -aige, from Proto-Celtic *sagyos (“seeker”).^[1]

• -aidhe, -oidhe, -uidhe (obsolete)
• -í (slender form)
• -idhe (obsolete slender form)

-aí m

1. Agent suffix

   ‎roth (“wheel”) + ‎-aí → ‎rothaí (“cyclist”)

From Old Irish -ide, variant form of -de used after a syncopated vowel.

• -aidhe, -idhe (superseded)
• -í (slender form)

-aí

1. Added to nouns to form adjectives.

• -í (slender form)

-aí m

1. Suffix used to form verbal nouns

   ‎tosaigh + ‎-aí → ‎tosaí

   ‎fiafraigh + ‎-aí → ‎fiafraí