What is the primary difference in meaning conveyed by using the imperfective aspect versus the perfective aspect when describing a repeated action in the past?

The primary difference when describing a repeated action in the past using imperfective versus perfective aspect in Polish lies in whether the focus is on the process or the completion of the action. Imperfective aspect emphasizes the repeated action as an ongoing process or a habitual occurrence without specifying completion of each instance. Perfective aspect, while less common for repeated actions, would emphasize the completion of each instance within the repeated set, or the accomplishment of the entire series of actions. Aspect in Polish refers to how the verb portrays the action with respect to time; it's not about *whensomething happened, but *howit happened. For example, 'Czytałem książki' (I was reading books) uses the imperfective aspect and implies a general habit of reading, focusing on the activity itself over a period of time. It doesn't suggest each book was necessarily finished. In contrast, using the perfective aspect for a truly repeated action is less natural and might require recasting the sentence to focus on the completion of a set of tasks, which would rarely apply to 'reading books'. If you were to use a perfective verb to describe the repeated action (which would be unusual, but possible with specific adverbs or contexts), it would highlight that each instance of reading was completed and that there was a finite set of such completions. This distinction is key to conveying precise meanings about habitual actions in the past.