Agent case marking in Sahaptian
The two languages of the Sahaptian language family, Ichishkíin/Sahaptin and Nez Perce, have split ergative case marking. Only third person agents take ergative case marking, never SAP agents. The Ichishkíin system is further split: one of two ergative makers is used depending on whether the patient is a speech act participant (SAP) or a topical third person, and not every third person agent is marked. The two languages demonstrate different strategies for extending ergative case marking from only scenarios where third persons act on speech act participants, to a broader range of third person agent marking.