I am no expert, yet I know that explanation is wrong. Have been forms the present perfect progressive tense, which can be used for completed actions and actions in progress. Have forms the present perfect tense.
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chiachen an expert in English language and writingWhy do you think that, chiachen? Can you post a link if s/he's on the internet?
chiachen one top favored expert who has over 36 years teaching experience,
Ah, a newbie.
I copied his answer in its entirety. And can you give us a link? I don't see any category for English or English Grammar on their homepage.
Amir,
Have been makes a verb past perfect and implies completed action. So have been