-oi-
Finnish
Etymology
The -i- has labialized the preceding -a-.
Infix
-oi- (front vowel harmony variant -öi-)
- Alternative form of -i- (“plural infix”)
- kasassa - kasoissa ― in the pile - in the piles
Usage notes
- if the plural indicator is between two vowels it becomes -oj-
- kasan - kasojen ― of the pile - of the piles