Formula/Rule of Present Perfect Continuous Tense:
(+) S + have/has + been + V-ing
(-) S + have/has + not + been + V-ing
(?) Have/has + S + been + V-ing
Find here Example of Present Perfect Continuous Tense:
(+) He has been playing guitar for two hours.
(-) He has not been playing guitar for two hours.
(?) Has he been playing guitar for two hours?
Yes, he has. / No, he has not.
