ergativity

noun

1. (uncountable)The property of a grammar's (or, by extension, a language's) being ergative; the attribute of possessing a grammatical pattern such that the object of a transitive verb is treated the same way as the subject of an intransitive one, while the subject of the transitive verb is treated differently.

   “We can speak of ergative/absolutive organization whenever intransitive subjects pattern with transitive objects (to the exclusion of transitive subjects). So defined, ergativity is independent of case marking and has many linguistic manifestations, some being observable in any given language. At the same time, ergativity competes with accusativity even in languages where it represents the predominant pattern.”

   “Ergativity is thus complementary to the familiar grammatical pattern of accusativity, in which one case (nominative) marks both intransitive and transitive subject, with another case (accusative) being employed for transitive object.”