Structure of sentence:
Main verb: Present participle (base form+ing).
E.g: Eating, Playing, reading etc.
Auxiliary verb: Have been, has been.
Note: If the subject of a sentence is “I, we, you, they or a plural noun”, the auxiliary verb ‘have been’ is used.
If the subject of a sentence is “he, she, it or a singular noun”, the auxiliary verb ‘has been’ is used.
The formula for present perfect continuous (Positive) is :
Subject+Auxiliary verb+Main verb(ing form) .
|I have been writing.||I have not been writing.||Have I been writing?|
|We have been writing.||We have not been writing.||Have we been writing?|
|You have been writing.||You have not been writing.||Have you been writing?|
|He has been writing.||He has not been writing.||Has he been writing?|
|She has been writing.||She has not been writing.||Has she been writing?|
|It has been writing.||It has not been writing.||Has it been writing?|
|They have been writing.||They have not been writing.||Have they been writing?|
I.This tense is used to express an action that started in the past and continued to present or recently stopped. It is used to state an ongoing action that has started at a point in the past. A time reference is also used in the sentence to show that when the action started in the past or how long the action continued.
He has been using his car for last 3 years. (Positive sentence)
They have not been studying books since Monday. (Negative sentence)
Has she been working as teacher for last 5 years? (Interrogative sentence)
The specific words (prepositions) ‘Since ’and ‘For’ are used in sentence to show the time of action.
Since is used if the exact time of starting of action is known or if we intend to reflect in the sentence.
E.g: since Monday, since 6am etc.
The word ‘for’ is used for the amount of time of action that is continued.
E.g: for two hours, for five months, for three weeks etc.
Point of time (since): E.g. She has been living in New York since 2005.
Amount of time (for): E.g. They have been watching the movie for 3 hours.
This tense is also used for the actions that are finished, But we are interested in the result.
E.g : It has been raining (= and the streets are still wet).
Someone has been eating my chips (= half of them have gone).