From a merger of at least two Proto-Indo-European suffixes:
- *-eyé-, a compound suffix of the morphemes below. Cognates include most Latin -īre (fourth conjugation) verbs, some -ēre (second conjugation) verbs, some Germanic *-janą verbs, Sanskrit denominative verbs in [script needed] (-áyati)[Devanagari needed].
- *-éye- (causative suffix). Cognates include Latin causatives in -ēre (second conjugation), some Germanic causative *-janą verbs, Sanskrit causative verbs in [script needed] (-áyati)[Devanagari needed].
There may be others.
-έω • (-éō)
- Used to form verbs from nouns, adjectives and other verbs.