What is perfect progressive aspect?

Related questions

1. What are the 3 progressive tenses?
2. When should I use present perfect?
3. Where do we use ago before and?
4. What is the rule of present indefinite tense?
5. When can I use present perfect?
6. What is a progressive verb example?
7. What are Progressive perfect verbs?
8. When Use present perfect progressive?
9. What is the structure of present indefinite tense?
10. What is past progressive tense with examples?

Tags

1. #present
2. #progressive
3. #action
4. #aspect
5. #going
6. #verbs
7. #future
8. #exception
9. #perfect
10. #tense