present perfect
forms
must put Have or has + without specific time
:ex
Ahmed has studied very hard
past perfect
must put Have or has +specific time
ex:
Ahmed has drank tea at 12
::note::
Do n’t use During in past perfect
can we use Since in the past perfect
:ex
I was in Saudi Arabia during the war
in past prefect
I have been in Saudi Arabia since twenty years
with my thanks to you
I was hope this subject was useful to you
[[[[thank you]]]]
Thank you for your effort