It is generally acknowledged that this verb is equivalent to com- + tóe (“silent”) suffixed with an unknown element that resulted in Old Irish -ss- /s/. It cannot be directly from a Proto-Celtic *tausyeti since the root-final s would have disappeared in such a formation.
con·túaisi (verbal noun coitsecht)
| 1st sg. | 2nd sg. | 3rd sg. | 1st pl. | 2nd pl. | 3rd pl. | Passive sg. | Passive pl. | ||
|---|---|---|---|---|---|---|---|---|---|
| Present indicative | Deut. | con·túaisi | con·tóiset | ||||||
| Prot. | ·coiset | ||||||||
| Imperfect indicative | Deut. | con·túaised | |||||||
| Prot. | ·coistithe | ||||||||
| Preterite | Deut. | con·túaisiset | |||||||
| Prot. | |||||||||
| Perfect | Deut. | ||||||||
| Prot. | |||||||||
| Future | Deut. | ||||||||
| Prot. | ·coistifet | ||||||||
| Conditional | Deut. | ||||||||
| Prot. | |||||||||
| Present subjunctive | Deut. | con·túaisi | |||||||
| Prot. | ·coitsea | ·coitsid | |||||||
| Past subjunctive | Deut. | ||||||||
| Prot. | |||||||||
| Imperative | caisted | caistid | |||||||
| Verbal noun | coitsecht | ||||||||
| Past participle | |||||||||
| Verbal of necessity | caistide | ||||||||
All modern descendants of this verb suffered from conflation with ro·cluinethar (“to hear”) and its verbal noun clúas.
| Old Irish mutation | ||
|---|---|---|
| Radical | Lenition | Nasalization |
| con·túaisi | con·thúaisi | con·túaisi pronounced with /-d(ʲ)-/ |
| Note: Some of these forms may be hypothetical. Not every possible mutated form of every word actually occurs. | ||