Present Perfect Continuous Tense

What is Present Perfect Continuous Tense

1. The easiest way to understand Present perfect tense is to understand Present continuous tense first.
There is just a little difference between them.
We use Present continuous tense to talk about an ongoing action, that is happening now. But in Present continuous tense, we don't use time period or time duration.
For example:
I am writing. (but since when or for how many hours?)
I am eating. 
He is sleeping. (since when?)

If you want to use time period or time duration, then look at these sentences;
For example:
*raining since morning?
It has been raining since morning.
(It is raining since morning)
*playing for 2 hours?
Ismail has been playing for 2 hours.
(Ismail is playing for 2 hours)
*sleeping since last night
He has been sleeping since last night.
(He is sleeping since last night.)

2. Present perfect continuous tense is also used to talk about a particular situation or state that somebody or something is in.
In this sense, Present perfect continuous tense is made from Present simple tense.
For example:
*sick for 2 days?
He has been sick for 2 days.
(He is sick for 2 days.)
*in Pakistan since 1940?
She has been in Pakistan since 1940.
(She is in Pakistan since 1940.)

Sentence Structure of Present Perfect Continuous Tense:

Positive:
Subject + has/have been + ing form of verb + sine/for...
He + has + been + playing + since morning.
Negative:
Subject + has/have not been + ing form of verb + since/for...
She + has  been + sleeping + for 2 hours.
Interrogative:
Has/Have + subject + been + ing form of verb + since/for...?
Have + they + been + working + for a week?