S-/Z- and the Grammaticalization of Aspect in Slavic

It is argued that the phonetic coalescence of *sъ- and *jьz into a single prefix resulted in the (partial) grammaticalization of innovative s-/z- as the primary préverbe vide of the aspectual systems in a group of western languages (Czech, Slovak, Sorbian, Slovene). The other Slavic languages either did not grammaticalize a single prefix (Croatian/Serbian) or have grammaticalized po- as their sole or primary préverbe vide (Russian, Bulgarian, Macedonian, Ukrainian, Belarusian); one Slavic language has near equal productivity of s-/z- and po- (Polish).