Infixation is a morphological process whereby a bound morpheme attaches within a root or stem.
The kind of affix involved in this process is called an infix.
(Phillipines - Tagalog)
The focus marker -um- is a infix which is added after the first consonant of the root.
- bili: root ‘buy’
- -um-: infix ‘AGT’
- bumili: word ‘bought’