How do you use past perfect continuous?

Related questions

1. What's the difference between past perfect and past perfect continuous?
2. What is the structure of the present perfect continuous tense?
3. Why present perfect tense is used?
4. When we use future perfect continuous tense?
5. What are some examples of present perfect tense?
6. Where present perfect tense is used?
7. What is the present perfect tense of teach?
8. What are present perfect tense examples?
9. When use the present perfect continuous?
10. What are perfect tenses in English?

Tags

1. #something
2. #which
3. #continued
4. #weeks
5. #continuous
6. #until
7. #duration
8. #minutes
9. #perfect
10. #before
11. #started
12. #another
13. #durations