s u n n y s i d e u p.

1. The Present Perfect Tense ( Have/has + past participle )

Before going further, you must understand the three forms of Verbs. A few examples are given below and go to the link for more examples.

http://esl.about.com/library/weekly/aa122197.htm

What ?

a) Present perfect has a connection with the situation now.
b) It tells us about something that happened before now without saying exactly when
c) It may also talk about something that happened in the past and still happening at the time of speaking when you use words like 'since' and 'for'.
d) You can also include the words , ‘just’, ‘not’ , ‘already’ after 'has', 'have', and 'had' with the present perfect.


Eg.

He told me his address but I have forgotten it.
She told us about her new car but we have not seen it.
I have just finished my posting.
She has already gone back to her hometown