ness < -on -us vs -tion

𓂋 𓋴 𓌘 𓁹 | vigilant | regardful
𓂋 𓋴 𓌙 𓄛 𓍑 𓏏 𓏴 | vigilance| regardfulness

-us ⇔ Germanic *-assuz *-þuz -άζω (-ázō).

⇔ *-atjaną -at-gen