The article discusses the relationship between the concepts of synonymy and paronymy, as well as the functioning in the language of prefixal verbal paronyms. The definition of paronyms as common-rooted words with different affixes, which are regularly misused in speech as synonyms, is clarified. Some verbs on the synchronic level may be considered as synonyms or as paronyms, depending on the focus of the speaker’s or listener’s attention. As for the diachronic aspect of language study, there are processes of synonymization of common-root prefixal verbs, associated mainly with hypo-hyperonymic relations between lexical units. The possibility of synonymous use of common-root words is determined by the proximity of prefixes’ meanings, neutralization of the context and the norm’s inattention to changes in usage. The norm can either leave unnoticed the appearance of a new way of expressing linguistic meaning, or mark the changes in dictionaries, fixing the word as a synonym. Sometimes it can also insist on the preservation of paronymic distinctions even when there are already no such distinctions in usage. Thus, the paronyms remain the common-rooted words, which, mixing in speech usage, draw the norm’s attention to themselves.