The Perfect Tenses: grammar rules, examples and when to use.
present perfect
past perfect
future perfect

The Present Perfect

The Formation of the Present Perfect

Affirmative	Interrogative	Negative
I have worked. He has worked. She has worked. It has worked. We have worked. You have worked. They have worked.	Have I worked? Has he worked? Has she worked? Has it worked? Have we worked? Have you worked? Have they worked?	I have not worked. He has not worked. She has not worked. It has not worked. We have not worked. You have not worked. They have not worked.

(Verb Contractions: I have = I�ve; he has = he�s; she has = she�s; it has = it�s; we have = we�ve; you have = you�ve; they have = they�ve)

The Present Perfect denotes:
1) a completed action closely connected with the present when the time os the action is indefinite.

Key example:
Mr. Smith has finished his work. He can rest now.

For study:
Note: - The Present Perfect is not used when the time of the action in the past is definite, e.g.: I finished my work at 8 o�clock.