This paper examines the semantic and morphosyntactic complementation patterns of perception verbs in Brazilian Portuguese. Using the framework of Functional Discourse Grammar, five semantic complement types are identified. It is subsequently shown that these five types are in an implicational relationship, such that the set of semantic complement types that a certain perception verb in Brazilian Portuguese may take occupies a contiguous segment on a hierarchy of semantic complement types. The morphosyntactic complements of perception verbs in Brazilian Portuguese include noun phrases, finite, and non-finite clauses, the latter comprising progressive1 and infinitival forms. The second part of the study shows that the choice for one of these types can to a high extent be predicted from the semantics of the complements, using the same hierarchy of semantic complement types.