The adjutative voice is a grammatical voice carrying the meaning "to help to". The subject of a verb in the adjutative voice is not an agent of the action denoted by the verb, but assists the (unstated) agent in performing the action.

For example, in Xamtanga language adjutative voice is formed by total reduplication of the verbal stem, insertion of the linking vowel-ə, and the suffixation of the causative suffix-s to the verbal stems.

"adəruØ guləʃət lɨwəʃən dʒɨβə dʒɨβɨsØu." Aderu helped Guleshe to buy the cow.