This thesis explores adverb distribution in Iquito, a Zaparoan language spoken byapproximately 25 people in the northern Amazon Basin of Peru. The syntactic distributions of Iquito adverbs correspond to four semantic classes: time, manner,epistemic, and an intensifier. Time adverbs have the broadest distribution, occurring before the topic of a topicalized sentence, between topic and subject, after the verb, and after the object of a transitive sentence. Manner adverbs have a similar distribution, but are not found before topic. Epistemic adverbs have an even narrower distribution, never occurring sentence-initially (whether the sentence is topicalized or not) and rarely occurring between topic and subject. The intensifier adverb has the most restricted distribution, as it only occurs before adjectives or other adverbs. These distributions can be used to classify "atypical" adverbs, namely infinitival verbs that are used adverbially. Furthermore, these distributions shed light on the phrase structure of Iquito. Adverbs are analyzed in the literature as adjuncts, and the allowable positions are explained either as the result of adjunction to different constituents (Ernst 2002; Iatridou 1990) or movement between adjoined positions (Cinque 1999). The pre-verbal positions of Iquito adverbs, particularly in irrealis and negated constructions, raise questions for these analyses. The data demonstrate that adverbs can occupy non-adjoined positions, namely the object position in an irrealis (SOV) construction and possibly negation, forcing a reevaluation of the current treatment of adverbs. The research also expands the existing documentation on Iquito. / text