Аннотация:Upper Kuskokwim is an Athabaskan language of interior Alaska. Upper Kuskokwim has two sets of verb roots, semantically specified for class afflilation of the Absolutive argument. The roots of the first set designate being in a position (‘lie’, ‘stay’), and the roots of the second mean independent motion (‘move’, ‘fall’). When causativized, the verbs of the second set predictably mean ‘throw’ or ‘drop’. Verbs such as ‘carry’ or ‘bring’, surprisingly, are based on the roots of being in a position. An explanation is offered to this phenomenon, involving the notion of frame of reference. An additional complication is associated with animate patients. This can be explained as a hybrid relative/independent frame of reference.