The prefixes are either aith- + ar- or aith- + ess-. The root was formerly believed to be Proto-Celtic *regeti, from Proto-Indo-European *h₃reǵ-. Nowadays however an unrelated verb *reketi is instead reconstructed as the root of ad·eirrig,[1] in consideration of Brythonic relatives like Cornish edrek (“regret”).[2]
ad·eirrig (prototonic ·aithirrig, verbal noun aithirge or aitherrach)
For quotations using this term, see Citations:adeirrig.
| 1st sg. | 2nd sg. | 3rd sg. | 1st pl. | 2nd pl. | 3rd pl. | Passive sg. | Passive pl. | ||
|---|---|---|---|---|---|---|---|---|---|
| Present indicative | Deut. | ad·errig, ad·eirrig; atann·eirrig (with infixed pronoun dan-) | |||||||
| Prot. | |||||||||
| Imperfect indicative | Deut. | ||||||||
| Prot. | |||||||||
| Preterite | Deut. | ||||||||
| Prot. | ·atherracht, ·aitherracht | ||||||||
| Perfect | Deut. | ||||||||
| Prot. | |||||||||
| Future | Deut. | ad·errius | ad·ersetar | ||||||
| Prot. | ·aithir | ·aithirsid | ·aithirset | ·aithirrestar | |||||
| Conditional | Deut. | ||||||||
| Prot. | |||||||||
| Present subjunctive | Deut. | ad·errius | ad·ersetar | ||||||
| Prot. | ·aithir | ·aithirsid | ·aithirset | ·aithirrestar | |||||
| Past subjunctive | Deut. | ||||||||
| Prot. | |||||||||
| Imperative | aithirgid | ||||||||
| Verbal noun | aithirge, aitherrach | ||||||||
| Past participle | |||||||||
| Verbal of necessity | |||||||||
| Old Irish mutation | ||
|---|---|---|
| Radical | Lenition | Nasalization |
| ad·eirrig (pronounced with /h/ in h-prothesis environments) |
unchanged | ad·n-eirrig |
| Note: Some of these forms may be hypothetical. Not every possible mutated form of every word actually occurs. | ||