Two-Ending Adjectives: 3rd Declension (3-3) -(ι)ων -(ι)ον

31.5 Adjectives ending in –(ί)ων –(ι)ον

(cf. S 293, G 149)

Notice that the inflection of –(ί)ων –(ι)ον. adjectives is similar to nouns ending in –(ι)ον that we have already studied, e.g. δαίμων δαίμονος. Note that:

• In the MASCULINE/FEMININE nominative singular, –(ι)ονς becomes –(ί)ων due to the loss of the sigma, and subsequent compensatory lengthening.
• In the dative plural of all genders, the –ν of –ονσι has dropped out, leaving only –οσι. 
• Finally, note that all of the –(ί)ων –(ι)ον adjectives in our vocabulary are COMPARATIVE adjectives: better, more, smaller, etc. For these set of comparative adjectives, -ω was regularly used by some authors as an alternative to the -ονα ending. For example:
  • βελτίονα→ βελτίω
  • πλείονα→ πλείω
  • ἐλάττονα→ ἐλάττω