1.You have no idea how long we've been searching for you.
2.I have been waiting for this for a long time.
In sentence 1, a guy who said it just found a guy. Why isn't this past-perfect? The action search is finished, right?
2, too. A guy who wanted to kill a girl just found her. The action wait is finished, right?
I believe that both sentences are in the present perfect progressive: have + been + - ing verb. They suggest an action or a process not yet finished (about to end though) or past activity that extends to the present. Having said that both tenses, that is, present perfect and present perfect progressive sometimes are interchangeable.
