What is the structure of present perfect?

Related questions

1. How do you present perfect tense?
2. What is the form of present continuous?
3. How do you write ing form?
4. What is formula of simple present tense?
5. What is the difference between present participle and present continuous?

Tags

1. #structure
2. #simple
3. #participle
4. #present
5. #using
6. #verbs
7. #perfect
8. #auxiliary
9. #regular