The thesis presents a study of the nontrivial interface of morphology, phonology and semantics found in the distribution of three Russian aspectual prefixes O, OB and OBO. These prefixes can be semantically identical when occur in the forms of the same paradigm (e.g. obo-drat’.INF. vs. ob-deru.1 PERSON.SG.FUT. ‘flay’), but can also carry strikingly different meanings that even yield minimal pairs ...