1380; from Old French oïl (1100), compound of o affirmative particle (compare Occitan òc ‘yes’) and il ‘he, him’, akin to o-je, o nos, o vos, all ‘yes’ constructed with pronouns. O and òc are both from Latin hoc ‘this’. Compare Portuguese isso ‘yes, yeah’, literally ‘this, that’. And the semantic shift is calqued on Gaulish: Compare Old Irish tó ‘yes’, Welsh do ‘indeed’, from Proto-Indo-European *tod (neuter) ‘this, that’.
This word is treated as if it has an aspirated h despite not being written with an h.
- Maori: Wīwī (“France”)
- si ("yes" used to contradict a negative statement or question)
- “oui” in le Trésor de la langue française informatisé (The Digitized Treasury of the French Language).