Proto-Indo-European verb and Slavic etymology

In Balto-Slavic, the large scope of stem variation within the verbal system inherited from Proto-Indo-European was reduced, on the paradigmatic level, to few apophonic verbs, reduplicated and nasal presents, but the former variety left traces in the lexicon, as alternate stems of an original paradigm gave rise to new paradigms, formally independent and semantically distinguished from each other. Bearing in mind this process may be helpful in solving etymological dilemmas and reconsidering problematic etymologies. This possibility is illustrated here by four instances of an etymological connection reestablishable, in Slavic, between apparently unrelated verbal stems if taking into account the Proto Indo European verb morphonology.