What does the present perfect tense express?

Related questions

1. What is progressive example?
2. What is past progressive tense with examples?
3. Is ago an adverb of time?
4. What is the formula for present perfect continuous tense?
5. What is the structure of present indefinite tense?
6. What does present perfect progressive mean?
7. When Use present perfect progressive?
8. When should we use present perfect tense?
9. What is simple and progressive aspect?
10. When can I use present perfect?

Tags

1. #perfect
2. #started
3. #subject
4. #tense
5. #express
6. #present
7. #continue
8. #before
9. #duration
10. #actions
11. #occurred
12. #formed
13. #participle
14. #unspecified
15. #summary