||The main premise of this thesis is that subject agreement morphology in Tuyuca can be isolated from the rest of the morphology. Subject agreement appears on evidentials, nominalizers, animate classifiers, gerunds, and verb stems requiring an auxiliary. This agreement is instantiated by a pervasive final vowel pattern that codes various values of gender, number, and person features. These final vowels also code the same information on nouns and pronouns. Before arguing for my analysis I provide some preliminary material on Tuyuca. Chapter 1 is a brief discussion of the sociolinguistic context of the language. Chapter 2 discusses issues relevant to Tuyuca data and surveys some of the literature related to Tuyuca; it also discusses some methodological concerns arising from the data and important to the thesis in general. Chapter 3 is a brief sketch of Tuyuca grammar important to agreement. Analysis is done in Chapters 4 and 5. In Chapter 4 I argue, in a descriptive-typological framework, that by isolating agreement a general deverbalizing function can be seen coded in the morpheme /-g-/. This morpheme has predictable interpretations in restricted morphosyntactic environments. It can be interpreted as a progressive or perfective aspect, an animate classifier, a gerund, and a nominalizer. In Chapter 5 I relate the general premise of isolating agreement in Tuyuca to theoretical issues belonging to the Minimalist Program. I show that isolating agreement morphemes from evidentials is, assuming the analysis in Chapter 4, straightforward. This has a practical advantage of making it easier to observe variation between present tense and past tense morphology of the evidentials. I take this as straightforward evidence that tense is fused with evidential. I also give evidence that supports the pro-drop status of Tuyuca, conjecturing that subject agreement is packaged with nominative case. I also argue informally that verbal inflection of tense-evidentials and subject agreement are "extensions" of the verb phrase and relate the predication of VP to some speech time and discourse situation of the verb event, relative to some specific world. This results in a model of functional hierarchy that places Evidential under Tense Phrase. I conjecture that this Evidential position is a predicational one, in contrast to the more accepted notions of Mood[evidential] or Modal[epistemic], which are known to be above Tense Phrase. I provide two detailed models, one with the conventional hierarchy and one with my hierarchy, arguing for the latter--based on general principles of syntactic economy and locality. I also provide a technical analysis of syntactic locality for the morphosyntactic fusion of tenseevidentials in a Distributed Morphology framework.