What is perfect aspect in grammar?

Related questions

1. What is perfect past tense with example?
2. What are the forms and functions of present perfect tense?
3. How do we use present perfect tense?
4. What are the rules of present perfect tense?
5. What is the use of ago?
6. What is past tense and types?
7. Does present perfect tense?
8. What's the difference between present perfect and present perfect continuous?
9. Is ago a preposition?
10. What is the structure of present perfect tense?

Tags

1. #which
2. #aspect
3. #tense
4. #complete
5. #sometimes
6. #expresses
7. #verbs
8. #perfect
9. #called
10. #completed
11. #action