What are Progressive perfect verbs?

Related questions

1. What is the structure of present indefinite tense?
2. What is the formula for present perfect continuous tense?
3. Can we use ago with present perfect?
4. What is past progressive tense with examples?
5. What is the rule of present indefinite tense?
6. What is a progressive perfect verb?
7. What does the present perfect tense express?
8. What is the past perfect progressive?
9. When should I use present perfect?
10. Is ago an adverb of time?

Tags

1. #three
2. #progressive
3. #participle
4. #progress
5. #verbs
6. #point
7. #action
8. #tense
9. #tenses
10. #present
11. #future
12. #ongoing
13. #appear