What aspect of verbs does the present perfect progressive tense emphasize?

The present perfect progressive tense emphasizes the ongoing nature of actions that started in the past and continue into the present. This tense is formed using the auxiliary verbs "have" or "has" followed by "been" and the present participle of the verb (the "-ing" form). It highlights not just the action itself, but also its relevance to the present moment, illustrating that the action has been in progress for some time and may still be occurring. For example, in the sentence "She has been studying for three hours," the focus is on the duration and continuity of her studying, which began in the past and extends to the present. This aspect of the present perfect progressive tense provides context that differentiates it from other tenses that may emphasize completion or specific timing of actions.