Tenses Questions
The past perfect tense is used to describe an action that was completed before another past action or time. It is formed by using the auxiliary verb "had" followed by the past participle of the main verb. For example, "She had already finished her homework before her friends arrived."
On the other hand, the present perfect continuous tense is used to describe an action that started in the past and is still ongoing in the present. It is formed by using the auxiliary verb "have/has" followed by "been" and the present participle of the main verb. For example, "He has been studying for the exam all day."
In summary, the past perfect tense focuses on the completion of an action before a specific past time, while the present perfect continuous tense emphasizes the ongoing nature of an action from the past until the present.