Case Evolution

As languages evolve, case systems change. In Ancient Greek, for example, the genitive and ablative cases became combined, giving five cases, rather than the six retained in Latin. In modern Hindi, the Sanskrit cases have been reduced to two: a direct case (for subjects and direct objects) and an oblique case. In English, apart from the pronouns discussed above, case has vanished altogether except for the possessive/non-possessive dichotomy in nouns.

The evolution of the treatment of case relationships can be circular. Adpositions can become unstressed and sound like they are an unstressed syllable of a neighboring word. A postposition can thus merge into the stem of a head noun, developing various forms depending on the phonological shape of the stem. Affixes can then be subject to various phonological processes such as assimilation, vowel centering to the schwa, phoneme loss, and fusion, and these processes can reduce or even eliminate the distinctions between cases. Languages can then compensate for the resulting loss of function by creating adpositions, thus coming full circle.