SummaryThis paper looks at the occurrence of o with intransitive verb oblique-case arguments and proposes a historical-functional explanation for the meanings of intendedness of the verbal action and total affectedness of the NP signalled by the postposition. The facts that (a) the same employment of the object marker is found in other Uralic-Altaic languages and (b) one or other of the same meanings is expressed in intransitive constructions by both the ergative marker in certain ergative languages and a verbal “extension” in the Bantu language Haya, are shown to support the proposed historical-functional view.