Not entirely clear. Possibly from Old Latin *insquom, compare īnsece and īnseque (“say!”, imperative). From Proto-Indo-European *h₁en-sékʷ-t, the *h₁en-prefixed form of the aorist stem of Proto-Indo-European *sekʷ- (“to say”) that has been thematicized in both Latin and Ancient Greek ἐνέπω (enépō, “to tell”).[1]
inquam (perfect active inquiī); irregular conjugation, irregular, highly defective
This verb is largely conjugated as if it were *inquiō (3rd conjugation) in present tenses and *inquō (also 3rd conjugation) in perfect tenses. However, there is an unusual first person singular present form inquam (cf. the athematic verb sum). This form is inherited from Proto-Indo-European *h₁en-sékʷ-m̥, the 1st person singular indicative of the aorist stem Proto-Indo-European *h₁en-sékʷ-t.
| indicative | singular | plural | |||||
|---|---|---|---|---|---|---|---|
| first | second | third | first | second | third | ||
| active | present | inquam | inquis | inquit | inquimus | inquitis | inquiunt |
| imperfect | — | — | inquiēbat | — | — | — | |
| future | — | inquiēs | inquiet | — | — | — | |
| perfect | inquiī | inquistī | inquit | — | — | — | |
| subjunctive | singular | plural | |||||
| first | second | third | first | second | third | ||
| active | present | — | — | inquiat | — | — | — |
| imperative | singular | plural | |||||
| first | second | third | first | second | third | ||
| active | present | — | inque | — | — | — | — |
| future | — | inquitō | inquitō | — | — | — | |
| non-finite forms | active | passive | |||||
| present | perfect | future | present | perfect | future | ||
| infinitives | — | — | — | — | — | — | |
| participles | inquiēns | — | — | — | — | — | |