From Proto-Indo-European *-istHos, from *-yōs (relative suffix) + *-tHós (adjectival suffix).[1][2] Cognate with Ancient Greek -ιστος (-istos), Proto-Indo-Iranian *-ištʰas.
*-istaz (adverb *-ist, comparative *-izô)
strong declension | ||||||
---|---|---|---|---|---|---|
masculine | feminine | neuter | ||||
singular | plural | singular | plural | singular | plural | |
nominative | *-istaz | *-istai | *-istō | *-istôz | *-istą, *-at(ō) | *-istō |
accusative | *-istanǭ | *-istanz | *-istǭ | *-istōz | *-istą, *-at(ō) | *-istō |
genitive | *-istas, *-istis | *-istaizǫ̂ | *-istaizōz | *-istaizǫ̂ | *-istas, *-istis | *-istaizǫ̂ |
dative | *-istammai | *-istaimaz | *-istaizōi | *-istaimaz | *-istammai | *-istaimaz |
instrumental | *-istanō | *-istaimiz | *-istaizō | *-istaimiz | *-istanō | *-istaimiz |
weak declension | ||||||
masculine | feminine | neuter | ||||
singular | plural | singular | plural | singular | plural | |
nominative | *-istô | *-istaniz | *-istǭ | *-istōniz | *-istô | *-istōnō |
accusative | *-istanų | *-istanunz | *-istōnų | *-istōnunz | *-istô | *-istōnō |
genitive | *-istiniz | *-istanǫ̂ | *-istōniz | *-istōnǫ̂ | *-istiniz | *-istanǫ̂ |
dative | *-istini | *-istammaz | *-istōni | *-istōmaz | *-istini | *-istammaz |
instrumental | *-istinē | *-istammiz | *-istōnē | *-istōmiz | *-istinē | *-istammiz |
This was the normal superlative suffix for all i-, u- and ja-stem adjectives. The regular a-stem adjectives sometimes used this suffix, and sometimes the related suffix *-ōstaz without any predictable rule.