We form the present perfect tense with HAVE or HAS plus the past participle of the principle verb. The past participle of regular verbs is the same as the past tense form. The past tense of irregular verbs must be memorized.
Examples:
Affirmative: I have finished my homework.
Negative: I haven’t finished my homework.
Interrogative: Have you finished your homework?
Affirmative: He has gone to Europe twice.
Negative: He hasn’t ever gone to Europe.
Interrogative: Has he ever gone to Europe?
Present perfect to express indefinite pastThe present perfect is used to talk about the indefinite past.
I have seen this movie twice. (I saw it once in 1986 and once in 1998.)
Click
here to see a list of verbs with irregular past participle forms.