Atle Grønn's dr. art thesis The Semantics and Pragmatics of the Russian Factual Imperfective is an investigation into some intriguing usages of the imperfective (Ipf), where Ipf denotes complete events. The so-called factual Ipf is a particularly interesting reading of Ipf, since it apparently functions on the territory of its competing aspectual rival, the perfective. Despite the prominent place of aspectual studies in Slavic linguistics, the role of factual Ipf in the aspectual system remains a major puzzle. The thesis argues that factual Ipf subsumes two quite different ways of referring to complete events - through asserting the existence of an event of the type of the verbal predicate (existential Ipf) or presupposing its existence (presuppositional Ipf). An entirely new formal machinery for treating information structure, notably the focus-background partitioning, is introduced in order to capture this distinction. Furthermore, in order to account for the interaction of aspect, tense and temporal adverbials a new temporal calculus for Russian is developed. Aspects are treated as relations between the event time and the assertion time (the speaker's focus), and the value of the latter is provided by tense and adverbials. The thesis gives empirical evidence for the use of factual Ipf with past perfect readings, and it is shown how these data can be accounted for in the temporal calculus. This is a non-trivial issue since the semantics in this case requires "two tenses" in the logical form, while the Russian sentence only exhibits one overt tense form. The analysis is carried out in a compositional version of the semantico-pragmatic framework Discourse Representation Theory, equipped with a neo-Davidsonian event semantics. This is the first time such an elaborate formal apparatus is applied to Russian aspect. The thesis provides a framework which may be of interest for formal studies of aspect in general.