Like other Numic languages (Uto-Aztecan), Northern Paiute has a morphological process of durative gemination, which conveys some type of aspect. I describe the semantics of durative gemination in Northern Paiute, locating it within an emerging typology of imperfective aspect from the formal semantics literature. Like the imperfective aspect in other languages, durative gemination has an event-in-progress interpretation, in addition to a number of other interpretations. Somewhat unexpectedly, one of these does not depict the internal structure of an event, but rather the event as a whole. I identify parallels between this completed interpretation for durative gemination in Northern Paiute and similar interpretations for the imperfective aspect in better-studied languages. * I am greatly indebted to Grace Dick, Edith McCann, and Madeline Stevens for continuing to teach me about their language over the years. In addition, I thank Pranav Anand, Isabelle Charnavel, and Sergei Tatevosov for their helpful discussion on a number of issues. I have also learned a lot from audience members at the annual meeting of the Society for the Study of Indigenous Languages of the Americas in Portland and Semantics of Under-Represented Languages in the Americas 8 at the University of British Columbia, as well as at Boston University and the University of California (Berkeley and Santa Cruz). 1 Transcriptions use IPA except y stands for [j], lenis b, d, and g are [b ∼ B], [R], and [g ∼ G] respectively, and double letters represent geminate consonants and long vowels. I use the following abbreviations: ACC = accusative, ADV = adverbial, COM = comitative, CONJ = conjunctive subject, CONT = continuous aspect, DEM = demonstrative, DIM = diminutive, DL = dual, DUR = durative gemination, EMPH = emphatic particle, EXCL = exclusive, F = feminine, GEN = genitive, HAB = habitual aspect, IMPF = imperfective aspect, INCEP = inceptive, INSTR = instrumental, INT = intensive, IP = instrumental prefix, LOC = postposition, NEG = negation, NMZ = nominalizer, NOM = nominative, PASS = passive, PAST = past tense, PERF = perfect aspect, PFV = perfective, PL = plural, PROG = progressive aspect, PROSP = prospective aspect, PRS = present tense, PTC = discourse particle, QUOT = quotative, REFL = possessive reflexive anaphor, SEQ = sequential suffix, SG = singular, SIM = simultaneous suffix, SUBJ = indicative subject.