What's the difference between past perfect and past perfect continuous?

Related questions

1. What are present perfect tense examples?
2. What is the structure of past perfect continuous tense?
3. What is the structure of present continuous?
4. What are examples of present perfect tense?
5. Is Present Perfect a past tense?
6. What is the structure of the present perfect continuous tense?
7. Where present perfect tense is used?
8. What is the past perfect continuous?
9. What is the present perfect tense of teach?
10. When use the present perfect continuous?

Tags

1. #formed
2. #noticed
3. #singular
4. #difference
5. #pronouns
6. #putting
7. #tenses
8. #subject
9. #continuous
10. #tense
11. #perfect
12. #between