Multifaceted body parts in Murui

Based on the firsthand data from Murui, a Witotoan language spoken in the Northwest Amazon, the study demonstrates how the body part terms ‘back’, ‘face’, ‘mouth, and ‘body’ grammaticalized into the domains covering spatial orientation, time, comparison, counting, and the reflexive. Murui body part nouns did not grammaticalize in isolation; to become grammatical markers, they were obligatorily followed by case marking. This allowed those nouns to preserve the original semantics of the case suffixes, and then to extend their semantics into other domains. For instance, the noun ‘back, spine’, followed by the locative, became a postposition meaning ‘above, on top’, and later also ‘over’, a marker used in comparative constructions and counting. In the contexts in which this process took place, ‘back’ lost its semantic content and many of its original morphosyntactic characteristics.