Present perfect continuous expresses an action that recently stopped or is still going on. It puts emphasis on the duration or course of the action.
Actions beginning in the past and still continuing (focus is on the action) – mostly with 'since' (a point of time) or 'for' (a period of time):I have been waiting for her for five hours
Recently completed actions:He has been watching too many videos.
Present perfect continuous has the meaning of 'lately'. If you use the present perfect continuous in a question such as 'Have you been feeling alright?', it can suggest that the person looks sick or unhealthy. It is possible to insult someone by using this tense incorrectly.
Form: have/has + been + infinitive + -ing  
I, you, we, theyhave been running.have not been running.Have you been running?
He, she, ithas been running.has not been running.Has it been running?
Formation of the present participle (often called the -ing or continuous form)
 adding -ing to the bare infinitive:work – working
Consonant after a short, stressed vowel at the end of the word
If the consonant is not stressed
double the consonant:
do not double it:
sit – sitting
benefit – benefiting
In British Englishdouble one -l at the end of the word:travel – travelling
One -e at the end of the word
Double -e
leave out the -e:
add -ing:
write – writing
see – seeing
Verbs ending in -iechange 'ie' to 'y':lie – lying
Verbs ending in -cchange 'c' to 'ck':picnic – picnicking
If the starting point is given,we use
I have been a teacher since 2004.
If the period of time is given,we use 'for'I have been a teacher for ten years.
Signal words:  'all day', 'the whole day', 'since', 'for'.
Questions with: 'how long'.