Réitíonn an aidiacht leis an ainmfhocal de réir tuisil agus inscne. Séimhítear aidiacht a cháilíonn ainmfhocal baininscneach sa tuiseal ainmneach, cuspóireach agus gairmeach uatha.
The adjective agrees with the noun in case and gender. An adjective is lenited when it qualifies a feminine noun in the nominative, accusative and vocative cases singular.
| Ainmfhocal firinscneach + aidiacht: A masculine noun + an adjective: | Ainmfhocal baininscneach + aidiacht: A feminine noun + an adjective: |
| lá maith (a) good day | oíche mhaith (a) good night |
| cúrsa deacair (a) difficult course | obair dheacair difficult work |
An aidiacht i ndiaidh réamhfhocail shimplí + an t‑alt + ainmfhocal.
The adjective after a simple preposition + the definite article + a noun.
| Ainmfhocal firinscneach: A masculine noun: | Ainmfhocal baininscneach: A feminine noun: |
| ar an lá deireanach on the last day | ar an oíche dheireanach on the last night |
| leis an bhfear bocht with the poor man | leis an mbean bhocht with the poor woman |
Nóta: I nGaeilge Uladh, séimhítear aidiacht a leanann ainmfhocal firinscneach a bhfuil réamhfhocal simplí agus an t‑alt ag teacht roimhe:
Note: in Ulster Irish, an adjective is lenited when it follows a masculine noun preceded by a simple preposition and the definite article:
ar an lá dheireanach
on the last day
leis an fhear bhocht
with the poor man
D, n t, l, s
Nuair a thagann na litreacha d, n, t, l, s le chéile ag deireadh ainmfhocail agus ag tús aidiachta, bíonn séimhiú fós i gceist.
When the letters d, n, t, l, s come together at the end of a noun and the start of an adjective, there is still lenition.
bialann Shíneach
(a) Chinese restaurant
bean dheas
(a) nice woman