IdentityàA sentence in present perfect tense tells that an action (denoted by verb) has been completed.
For exampleà “Ram has reached the school”. In this sentence action is “reach” that has been completed.
1) 3rd form of verb is used.
2) Helping verb à has/have is used with different subjects as
Hasà he, she, it, Name, other 3rd person singular subjects.
Haveà I, we, they, you and plural subjects.
1) Affirmativeà subject +has/have +verb +object.
2) Negativeà Subject+has/have+not+verb +object.
3) Interrogativeà Has/Have +subjects + verb +object?
4) Negative+ Interrogativeà has/ have +subjects + not +verb + objects?
1) She has completed her homework.
2) I have not stolen your money.
3) Have you ever seen a monkey?
4) He has not given me any book.
5) Has it happened before also?
For practice see