<![CDATA[The research is motivated by the limited comparative studies that systematically analyze clause transformation across local and international languages, particularly in identifying structural correspondences and divergences that may influence language learning. This study examines the similarities and differences in active and passive clause transformations between the Banggai language (Seasea dialect) and English. This research employed a qualitative descriptive design with a contrastive analysis approach. The data were obtained from five native speakers of the Banggai language from Babang and Pandaluk villages. Data collection was conducted through structured interviews. The data were analyzed using contrastive linguistic analysis, focusing on syntactic structures, verb forms, and sentence patterns in both languages. The results of the study revealed one similarity and three differences. The similarity lies in the pattern of movement transformation with non-human doer: S+P+O becomes S+P+A, which is similar in both languages. The differences include: (1) the deletion of agents is optional in English, but in Banggai (Seasea), human agents and agent determiner are obligatory deleted; (2) English inserts a new word, while Banggai (Seasea) does not; and (3) the verb changes to V3 in English, while Banggai (Seasea) uses the affix ‘in’ as prefix and infix. These findings extend current knowledge of cross-linguistic voice alternation by demonstrating that passive transformation cannot be explained solely through universal syntactic movement but must also account for language-specific morphological and grammatical mechanisms. The implications of this study offer useful insights for future studies in contrastive linguistics and may serve as a reference for researchers and educators interested in local language documentation and cross-linguistic analysis.]]>
