m jst nt undrstanding ,dat xactly how to aply haSs been ,have been n had been so plz tl me dis plz clar dis cncpt.....

Has been is applied when the sentence is in present perfect continuous tense and the subject is Third Person Singular like he, she, it.For example, He has been staying here for many days, She has been preparing for exam for many days,It has been raining since Friday.

Have been is applied when the sentence is in present perfect continuous tense and the subject is First Person singular/plural or Second person singular/plural or Third person plural.For example,I have been watching movie from many days, We have been playing cricket for many hours, You have been staying here from many years, They have been doing this work from many years.

Had been is used in past perfect continuous tense only.