From an earlier form *ercō, ercīre + -scō. *Ercō is probably from Proto-Indo-European *h₁erk- (“to divide”), cognate with Hittite (ark-). The spelling with initial h is by influence of the unrelated hērēs (“heir”).
ercīscō (present infinitive ercīscere); third conjugation, no passive, no perfect or supine stems
Usually found in the gerundive ercīscendus or (more often) ercīscundus.
| indicative | singular | plural | |||||
|---|---|---|---|---|---|---|---|
| first | second | third | first | second | third | ||
| active | present | ercīscō | ercīscis | ercīscit | ercīscimus | ercīscitis | ercīscunt |
| imperfect | ercīscēbam | ercīscēbās | ercīscēbat | ercīscēbāmus | ercīscēbātis | ercīscēbant | |
| future | ercīscam | ercīscēs | ercīscet | ercīscēmus | ercīscētis | ercīscent | |
| subjunctive | singular | plural | |||||
| first | second | third | first | second | third | ||
| active | present | ercīscam | ercīscās | ercīscat | ercīscāmus | ercīscātis | ercīscant |
| imperfect | ercīscerem | ercīscerēs | ercīsceret | ercīscerēmus | ercīscerētis | ercīscerent | |
| imperative | singular | plural | |||||
| first | second | third | first | second | third | ||
| active | present | — | ercīsce | — | — | ercīscite | — |
| future | — | ercīscitō | ercīscitō | — | ercīscitōte | ercīscuntō | |
| non-finite forms | active | passive | |||||
| present | perfect | future | present | perfect | future | ||
| infinitives | ercīscere | — | — | — | — | — | |
| participles | ercīscēns | — | — | — | — | ercīscendus, ercīscundus | |
| verbal nouns | gerund | supine | |||||
| genitive | dative | accusative | ablative | accusative | ablative | ||
| ercīscendī | ercīscendō | ercīscendum | ercīscendō | — | — | ||