I give an overview of the perfective and imperfective in Siamou, discussing phonological form, syntactic position (briefly), and meaning. I argue that the perfective is a low-tone suffix and that the imperfective is a mid-tone nasal suffix. I consider the possibility that perfective and imperfective aspect are syntactically lower than other aspects in Siamou. I show that the Siamou perfective and imperfective generally fit with cross-linguistic patterns for these aspects, including, for example, culmination entailments, but likely differ from other languages with regard to stative verbs.
