EXPESSES AN ACTION THAT STARTED IN THE PAST AND CONTINUES IN THE PRESENT.
Conjugation:
Subject + "have"(in the present) + past participle of verb
EX: *Certain words often accompany this verb tense: for, since, so far, up to now, up to the present, often, always, usually, never.
You have ignored the information for the past two years.
He has not worked for a mining company up to now.
Has Jim always lived in Ottawa?
IS USED TO PUT MORE OF AN EMPHASIS ON THE LENGTH OF AN ACTION THAT STARTED IN THE PAST AND CONTINUES TO THE PRESENT THAN THE PRESENT PERFECT
Conjugation:
Subject + "be"(in the present prefect) + base form of verb + ing
EX:
I have been studying ever since I arrived.
You have not been writing for the last three hours.
Has he been delivering the mail for a long time?