Inherited from Proto-Indo-European *-yéti (denominative suffix) attached to athematic stems. Cognates include Ancient Greek denominatives with -y- metathesis, verbs in -ίω (-íō) and -ύω (-úō), Sanskrit denominative verbs in -यति (-yáti).
*-(i)janą
Following a short stem, which consists of a short vowel followed by a single consonant, the suffix is *-janą.
Following a long stem, which has either a long vowel or diphthong, or a short vowel followed by multiple consonants, the suffix is *-ijaną.
This suffix remained productive only in Gothic. It was preserved in Old Norse but was no longer productive in that language, its function having been taken over by *-ōną. In West Germanic, it had already almost disappeared in most languages except after -r-, and was no longer productive in those that retained it.
From Proto-Indo-European *-éyeti (causative suffix). Cognates include most Latin -īre (fourth conjugation) verbs, some -ēre (second conjugation) verbs, Proto-Slavic *-iti causative verbs, most Ancient Greek -έω (-éō) contracted verbs, Sanskrit denominative verbs in -अयति (-ayáti).
*-(i)janą
Following a short stem, which consists of a short vowel followed by a single consonant, the suffix is *-janą.
Following a long stem, which has either a long vowel or diphthong, or a short vowel followed by several consonants, the suffix is *-ijaną.
From Proto-Indo-European *-eh₁yéti, an innovated compound suffix from *-éh₁ti (stative verb suffix) which was originally athematic, but later extended with the thematic present suffix *-yéti based on the past participle.[1] Cognate with Latin stative verbs in -ēre (second conjugation).
*-(i)janą
Following a short stem, which consists of a short vowel followed by a single consonant, the suffix is *-janą.
Following a long stem, which has either a long vowel or diphthong, or a short vowel followed by several consonants, the suffix is *-ijaną.
This suffix was no longer productive in any of the daughter languages, and in West Germanic it quickly became a relic class and mostly merged with the second weak class, except in Old High German where it was preserved longer. In Old High German and Gothic, the class of verbs formed by this suffix merged with those derived with *-āną, creating a single unified third weak class.