The paper is a preliminary exploration of the historical development of the
causative category on the basis of a comparison of more than 20 Tibeto-Bur
man languages. The methodology adopted is one of the comprehensive comparis
on between phonetic forms and semantic content and of the analysis of the l
anguage system (structural system and kinship language system). We conclude
that the causative category is one of the oldest and most general grammati
cal categories of Tibeto-Burman languages and its historical development is
constrained by prosodic, semantic and functional factors.