This paper discusses the emergence of the isomorphism between the causative and passive suffixes in Manchu-Tungusic languages, and argues that the transitivity of a sentence plays a pivotal role. It defines the transitivity of a sentence as the degree of individuation of the arguments, and proposes the grammaticalization path from causative to passive. In addition, it rejects the previously suggested route through the reflexive-causative, and suggests the direct grammaticalization path from the permissive-causative to the factitive-causative and the passive. It is due to the fact that the Manchu-Tungusic causative morpheme stems from the lexical verb which means ‘give’. In turn, The less agentive agent of the causative construction triggers the passive reading. Various pieces of evidence from cross-linguistic perspectives are provided in order to support the argument.
