The Perfect Progressive theory in Nepali grammar is used to describe actions that are ongoing or continuous in the past, but have been completed before a certain point in time. It is formed using the auxiliary verb “गर्दा हुनेछ” (garḍā hunēcha) followed by the present continuous tense of the main verb.

For example, let’s consider the sentence “किनकि तिमी एक साढे दुई घण्टा समय देखि नेपाली पढ्दै आएको हुनेछौ?” (Kinkī timī ēka sāḍhe duī ghanṭā samaya dēkhi Nepālī paḍhdai ā’ēkō hunēcha?) which translates to “Why have you been learning Nepali for an hour and a half?” Here we can see that the action of learning Nepali has been ongoing for a specific duration of time.

The Perfect Progressive theory is useful in expressing actions that started in the past and continued up until a certain point, highlighting the duration of time involved. It adds depth and precision to the description of events in the past.