In linguistic typology, split ergativity is a feature of certain languages where some constructions use ergative syntax and morphology, but other constructions show another pattern, usually nominative-accusative. The conditions in which ergative constructions are used varies from language to language.
Nominative-accusative languages (including European languages, with the notable exception of Basque) treat both the actor in a clause with a transitive verb and the experiencer in a clause with an intransitive verb in the same way grammatically. If the language uses case markers, they take the same case. If it uses word order, it is parallel.
For example, consider these two English sentences:
The grammatical role of "Jane" is identical. In both cases, "Jane" is the subject.
In ergative-absolutive languages (including the Basque, Georgian, Greenlandic and Mayan languages), there is a different pattern. The patient (or target) of a transitive verb and the experiencer of an intransitive verb are treated the same grammatically. If the two sentences above were expressed in an ergative language, "John" in the former and "Jane" in the latter would be parallel grammatically. Also, a different form (the ergative) would be used for "Jane" in the first sentence. (There is no easy way to represent that construction in English.)
In split ergative languages, some constructions pattern with nominative-accusative, and others with ergative-absolutive.
The split is usually conditioned by one of the following:
An example of split ergativity, conditioned by tense and aspect, is found in Hindustani (Hindi/Urdu), which has an ergative case on subjects in the perfective aspect for transitive verbs in the active voice. However, in all other aspects (habitual, progressive), subjects appear in the direct case.
In the following perfective sentence, the agent la?ke-ne is marked for ergative case, while the undergoer kit?b is in unmarked direct case. The verb khar?d? has the feminine ending -?, showing gender agreement with the undergoer kit?b.
In the corresponding imperfective sentence, the agent la?k? is in unmarked direct case. The verb khar?dt? has the masculine ending -? and thus agrees with the agent la?k?.
In transitive clauses, verbs are framed by a person marking prefix (called "set A" in Mayan linguistics) that expresses the subject, and a suffix that expresses the object (= "set B").
'You hug me.'
In intransitive clauses, the subject can either be represented by a set A-person marker, or a set B-person marker, depending on aspect.
In perfective aspect, Chol has ergative-absolutive alignment: the subject of the intransitive verb is expressed by a suffixed person marker, thus in the same way as the object of transitive verbs.
In imperfective aspect, Chol has nominative-accusative alignment: the subject of the intransitive verb is expressed by a prefixed person marker, thus in the same way as the subjct of transitive verbs.
In Columbia River Sahaptin, the split is determined by the person of both subject and object. The ergative suffix -n?m occurs only for third-person subjects for which the direct object is in the first or the second person.
Another ergative suffix, -in, marks the subject in the inverse. Both subject and object are then always in the third-person.
Direct (same as above example):