Split ergativity

Split ergativity is shown by languages that have a partly ergative behaviour but employ another syntax or morphology, usually accusative, in some contexts. In fact, most of the so-called ergative languages are not pure but split-ergative.

The split is usually conditioned by one of these:

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, but in all other aspects (habitual, progressive), subjects appear in the nominative case:

In the first sentence, the verb in present tense has the masculine ending -ā, agreeing with laṛkā (boy), but in the second sentence, the verb in past tense has the feminine ending -ī, agreeing with the feminine noun kitāb (book). "Boy" now appears as laṛke-ne, literally "by the boy".

In Columbia River Sahaptin the split is determined by the person of both subject and object. The ergative suffix -nɨm occurs only for third-person subjects when the direct object is first- or second-person.

Another ergative suffix -in marks the subject in the inverse. Both subject and object are always third-person in the inverse.

Direct (same as above example):

Inverse:

...
Wikipedia