Recent work in case theory has vigorously supported the idea that the ergative case identifies the agent (the intentful performer of an action) of a verb.
[4] In Kalaallisut (Greenlandic) for example, the ergative case is used to mark subjects of transitive verbs and possessors of nouns.
Nez Perce has a three-way nominal case system with both ergative (-nim) and accusative (-ne) plus an absolute (unmarked) case for intransitive subjects: hipáayna qíiwn ‘the old man arrived’; hipáayna wewúkiye ‘the elk arrived’; wewúkiyene péexne qíiwnim ‘the old man saw an elk’.
Sahaptin has an ergative noun case (with suffix -nɨm) that is limited to transitive constructions only when the direct object is 1st or 2nd person: iwapáatayaaš łmámanɨm ‘the old woman helped me’; paanáy iwapáataya łmáma ‘the old woman helped him/her’ (direct); páwapaataya łmámayin ‘the old woman helped him/her’ (inverse).
The ergative case is also a feature of some constructed languages such as Na'vi, Ithkuil and Black Speech.