Present Perfect Continuous

Formation
have/has been doing
I have been working. Have I been working? I have not been working.
for I / you/ we /they
She has been working. Has she been working? She has not been working.
for he /she / it

Use
the Present Perfect Continuous Inclusive:
1. is used to denote an action which began in the past, has been going on up to the present and is still going on (is generally used with since, for, these two days, etc.). If the conjunction since introduces a clause, the verb in this clause is in the Past Indefinite.
I have been working out for your white dress for the last ten minutes.
Ever since I saw you last I have been thinking, thinking.
With verbs not admitting of the Continuous form the Present Perfect Inclusive is the only tense possible.

in colloquial English
the verbs to want and to wish are often to be found in the Perfect Continuous form though, as stated above they are not used in the Continuous form.
I have been wishing to speak to you ever since you returned.
The Present Perfect Continuous Inclusive is rendered in Russian by the present.
I have been teaching at this school for 20 years.
Я преподаю в этой школе 20 лет.

The Present Perfect Continuous Exclusive:
2. denotes an action which was recently in progress but is no longer going on at the present moment.
You are not well today. You look distressed. You have been weeping.
The Present Perfect Continuous Exclusive is used to express repeated actions in the past.
How have you been spending your money?
I have been buying pictures.
I have been getting letters from him.

The Present Perfect Continuous Exclusive is often used with an emotional colouring.
I suppose you have been telling lies again.
The Present Perfect Continuous Exclusive is rendered in Russian by the past imperfective.
Your eyes are red. You have been crying.
У вас красные глаза. Вы плакали.

The Present Perfect Continuous Inclusive and the Present Continuous
Students should take care not to mix up the Present Perfect Continuous and the Present Continuous: the Present Continuous is used to denote an action going on at the present moment, no previous duration is expressed. The Present Perfect Continuous Inclusive is used when the previous duration of the action is expressed.
I am reading Dombey and Son.
I have been reading Dombey and Son for three days.
There is no difference in the translation.
Я читаю роман «Домби и сын».
Я читаю роман «Домби и сын» три дня.