We use Present Perfect Continuous and Present Perfect when action started in the past and continuous into the present.
Link for the same use in Present Perfect: Present Perfect Usage 1: Actions started in the past and continuing in the present
So, what is the difference between Present Perfect Continuous and Present Perfect, when it comes to actions started in the past and continuing in(to) the present?
Now we are talking about Duration (length) vs fact of action. These are the components:
1. Action started in the past
2. Action continues in(to) the present
3. We have indication of duration: for / since or their synonyms, or we can infer the fact of duration from the context.
3. We have indication of duration: for a period of time / since a moment or period of time, or their synonyms, or we can infer the fact of duration from the context.
Duration (length) of action vs fact of action
We use present perfect continuous to emphasize the length of the action in process, i.e. the length of time this action is taking. This is the reason why the verb takes so called continuous or “lengthy” form with the ing.
The Present Perfect emphasizes the fact of doing, rather than the length of doing:
They’ve been working for hours / since Wednesday! (emphasizes the length of time)
They’ve waited for hours / since 2 pm. (emphasizes the fact of waiting)
More on Present Perfect Continuous Tense: