The Past Perfect Progressive tense in Czech grammar is used to describe actions that were ongoing in the past and were completed before another past action. This tense can be formed by using the past participle of the verb “být” (to be) together with the past participle of the main verb, which is modified according to the gender and number of the subject. Unlike English, the Czech language does not have a continuous form of verbs, and the progressive aspect is usually expressed by adding qualifiers such as “právě” (just) or “stále” (still) to emphasize the ongoing nature of the action.