點樣用 will be / has been ?

WILL BE :
Tom will be fat later. (future tense - active)
My homework will be done by me later.(future tense - passive voice)
Tom will be doing homework at 10:00 tomorrow. (future continous tense - active)

HAS BEEN :
John has been a fireman for one month. (present perfect tense - active )
Mary has been killed by a murderer for 2 days.(present perfect tense - passive)
He has been living Hong Kong for 10 years (present perfect continous tense - active )

Will be = things happened in future , 將會
e.g. I will be free on Sat.
I will be there.

Has/have been = things just happened in a short period ago , 曾經
e.g. I have been to China for one month.
He has been visited his grandmother last week.

will be = future tense

has been = present perfect tense

Mary is a student. (present tense)

Karen will be a student next month. (future tense, John is not a student now, he will be a student in the future)

Som has been a student for one month. (present perfect tense)

verb: [be]
will be = future tense
has been = present perfect tense
John is a student. (present tense)
John will be a student next month. (future tense, John is not a student now, he will be a student in the future)
John has been a student for one month. (present perfect tense)