In this study, I present analyses of various aspects of Karitiana, a Tupi-Arikem language spoken in the state of Rondonia, in the Amazon region of Brazil. These analyses range in both methodology and scope, but are unified by the goal of elucidating articulatory, perceptual, and morphosyntactic patterns in the language. These patterns crystallize during the course of each of two parts of the dissertation. In the first part, I focus on the sound system of Karitiana. The investigation of the sound system includes detailed analyses of the phonemic inventory of the language, as well as basic phonological processes. However, the investigation also includes acoustic, quantitatively-oriented examinations of the vowel system, stop-vowel sequences, and patterns of velar lowering, among other phenomena. These studies focus on basic articulatory gestures in the language. Basic perceptual patterns, related to the typologically-unusual patterns of velar lowering in the language, are also considered in Part I, via the discussion of a speech-perception experiment carried out among the Karitiana. In Part II morphological and syntactic patterns in Karitiana are examined, within a functional-typological framework. Part II includes a grammatical sketch of Karitiana morphology and syntax, as well as more detailed studies of two basic aspects of Karitiana morphosyntax, namely grammatical relations and voice phenomena. I demonstrate that in some cases the latter sorts of phenomena reflect basic conceptual patterns, associated with the construal of event types, which are evident in the grammar of Karitiana.