FromProto-Celtic*adkʷissiyū, verbal noun of*adkʷiseti with the suffix*-tiyū.
| singular | dual | plural | |
|---|---|---|---|
| nominative | aicsiu | — | — |
| vocative | aicsiu | — | — |
| accusative | aicsinN | — | — |
| genitive | aicsen | — | — |
| dative | aicsinL,aicsiuL | — | — |
| radical | lenition | nasalization |
|---|---|---|
| aicsiu (pronounced with/h/ inh-prothesis environments) | aicsiu | n-aicsiu |
Note: Certain mutated forms of some words can never occur in Old Irish.
All possible mutated forms are displayed for convenience.