From a Proto-Indo-European suffix -tyen-, which consists of Proto-Indo-European *-ti- and Proto-Indo-European *-yen-. The suffix *-ti- is also contained in Proto-Indo-European *-tis.
-tiō f (genitive -tiōnis); third declension
- -tion, -ation, -ing; used to form a noun relating to some action.
The suffix -tiō is added to the supine form of a verb to create a third-declension noun naming the verb's action or the result of that action.
- dictātiō (“a dictating, dictation”), from dictātum, supine of dictō (“I dictate”)
- quadripartītiō (“a division into four parts”), from quadripartītum, supine of quadripartiō (“I divide in four parts”)
The suffix is occasionally added to other parts of speech, or appears in situations where no related verb apparently exists.
- gradātiō (“making of a staircase or steps”), from gradus (“step, pace”).
- mentiō (“a mention”), from mēns (“mind, disposition”)
- Malay: -si, -syen, -sen
- Maltese: -zjoni
- Norwegian: -sjon
- Occitan: -cion, -son
- Old Portuguese: -çon
- Polish: -cja
- Portuguese: -ção, -zão
- Romanian: -ție, -țiune, -ciune
- Romansch: -ziun, -schun
- Russian: -ция (-cija)
- Serbo-Croatian: -ција, -cija
- Sicilian: -zioni
- Slovene: -cija
- Spanish: -ción, -zón, -són
- Swedish: -tion
- ^ Jean Haudry, L'indo-européen; p. 55/56