Present Perfect Continuous is formed by means of the auxiliary verb have (has for 3rd person singular) in Present Tense plus been plus the verb with ending -ing.
For example:
I have been living in Rome for a year. (I’ve)
She has been living in Rome for a year. (She’s)
They have been living in Rome for a year. (They’ve)
I have not been living in Rome for a year. (I’ve not)
She has not been living in Rome for a year. (She’s not)
They have not been living in Rome for a year. (They’ve not)
Have I been living in Rome for a year?
Has she been living in Rome for a year?
Have they been living in Rome for a year?
Cases of using:
1.Actions started in the past and continuing up to the present
He’s been writing a letter for two hours. (He started two hours ago and he’s still writing it.)
2.Past actions of certain duration having visible results or effects in the present
She’s been crying. (Her eyes are red.)
3. Actions expressing anger irritation, annoyance, explanation or criticism
Who has been using my toothbrush? (annoyance)
4. Emphasis on duration (usually with for, since or how long)
She’s been calling on clients since this morning.
Time expressions used with:
how long, for, since
Note: verbs live, feel, work can be used in Present Perfect and Present Perfect Continuous with no difference in meaning.
I’ve been living / I’ve lived in Rome for a year.