The Austronesian Comparative Dictionary

Value -um-

Language:
Proto-South Sulawesi
Parameter:
verbal infix which "parallels //maN// to a considerable extent: as an "infinitive" or "participial" marker, or to mark transitive verbs with indefinite or implicit objects. In all of these the focus seems to be less on the agent than on the action itself, and in this respect it is noteworthy that /um/, unlike /maN/ can co-occur with clearly intransitive verbs (at least in the Sa'dan group) like 'sit', 'go' and 'walk'.". [b91dea83a5438c121a290cb14aeada2b]
References
Mills 1975