The story
- Proto-Indo-European*né
- Proto-Indo-European*n̥-
- Proto-Italic*n̥-
- Latinin-
- Latinim-
- Englishim-
- Proto-Indo-European*per-der.?
- Proto-Indo-European*pér
- Proto-Indo-European*pró
- Proto-Indo-European*pro-
- Proto-Italic*pro-
- Latinprō-
- Proto-Indo-European*dewk-
- Proto-Indo-European*déwkti
- Proto-Italic*doukō
- Latindūcō
- Latinprōdūcō
- Late Latinprōductīvus
- Englishproductive
- English todayimproductive
From im- + productive.
Etymology from Wiktionary, CC BY-SA 4.0.