A sentence in present perfect continuous tells two things (a) action (denoted by verb) is not completed. It is continue at the moment (b) starting time of action/work or period of time during which action is taking place is given.
1st form of verb is used.
2) “ing” is added to the 1st form of verb.
3) Helping verb à has been /have been is used with different subjects as
Has been à he, she, it, name, other 3rd person singular subjects.
Have been à I, we, you, they, plural subjects.
4) Before time Since/for is used .(see correct uses of since/for) .”Since” is used if ‘time of beginning of action’ is given and “for” is used if ‘period of time’ is given.
Affirmativeà Subjects +has been /have been +verb +object
Negativeà Subjects +has /have+not +been +verb +objects.
Interrogativeà Has/ Have +subject + been +verb +object?
Negative + Interrogative à Has/ Have +subject +not +been +verb +object?
1) He has been living in Mumbai since 1998.
2) They have not been going to school for 5 days.
3) Have you not been going to temple for two months?
4) He has not been eating since yesterday.
5) Has she not been working in this office for 2 months?
For practice see