Quote:
Originally Posted by GUEST  Also we can't use simple past instead of present perfect because,in simple past there is no effect of the event going on,but in present perfect the event begins in the past and still goes on.  |
Guest, I think you're confusing the present perfect (simple) with one (only) of the functions of the present perfect
progressive/continous.
You could look it up in the grammar glossary:
Search Results for 'present perfect' - UsingEnglish.com