Voice
Voice is a relational category because it's associated with the positions occupied by the NP arguments of a verb, rather than any inherent properties of the verb itself. The best-known voice contrast is that between ACTIVE and PASSIVE illustrated in (73) both from the Bantu language Chichewa, spoken in Malawi, and from the English translation. In both languages, (73a) is active and (73b) is passive (SU in the gloss is a 'subject marker')