How does the usage of a prefixed verb affect its aspectual properties, specifically when deriving a perfective verb from an imperfective one?

Adding a prefix to an imperfective Russian verb typically transforms it into a perfective verb, changing its aspectual properties. Aspect in Russian verbs indicates how an action is viewed: whether it is complete (perfective aspect) or ongoing/repeated/general (imperfective aspect). Prefixes drastically alter the meaning and almost always result in the verb becoming perfective, signifying a completed or single, bounded action. For example, the imperfective verb 'читать' (chitat') meaning 'to read' can be prefixed with 'про-' (pro-) to form 'прочитать' (prochitat') meaning 'to read completely' or 'to finish reading', making it perfective. The prefix adds a sense of completion, achievement of a result, or beginning/ending of the action. While the imperfective verb describes an action in progress or as a general activity, the newly formed perfective verb focuses on the achievement or completion of that action. The specific meaning added by the prefix varies, but the shift in aspect from imperfective to perfective is a consistent result. Some prefixes may not always create a perfective verb; in rare cases, the prefix may be used to derive a different imperfective verb with a slightly altered meaning, but this is less common. The derived perfective verb then typically forms a new imperfective partner using suffixes like -ыва- or -ва- creating an aspectual pair. An example would be 'решить' (reshit') 'to decide' (perfective), which can be turned back into imperfective 'решать' (reshat') 'to decide, to be deciding' through suffixation. The core principle is that prefixation is the primary means of creating a perfective verb from a base imperfective verb, thereby changing its aspectual properties to denote completeness, a single event, or a bounded action.