The present perfect continuous tense, also known as the present perfect progressive, is used to show that something started in the past but is continuing at the the present moment or has very recently finished.
It is formed by using have/has been + present particle (verb+ing):
So they started exercising at 3pm and they are still exercising at the point this affirmative statement is being made.
It can be shown on a timeline like this:
Remember it can also be abbreviated:
We don't tend to do this in formal writing, but we do it in informal writing or speaking
The affirmative, question, and negative forms are as follows:
Common words used with the present perfect continuous are lately/recently, for, and since.
This means that the headaches are still continuing now, but no specific time is given.
Or if we wish to be more specific with times:
In all of these cases, it is being made clear the problem started in the past, has been continuous, and is still a problem now.
The present perfect continuous tense focuses on the fact that an activity has been repeated or is continuous. But this can still be going or have just stopped.
In this first example the activity is continuing:
In this case, however, it has just stopped.
Either way though, the sentences emphasise the repetition of the activity i.e. the continuous jogging in this case.
Generally stative verbs, or verbs representing a state of mind, are not used in the present continuous tenses. With most stative verbs in the present perfect continuous tense, this is also the case.
For example, we cannot say this:
In these cases we use the present perfect simple:
However, it is not quite as strict as the present continuous, and with some verbs, particularly those that show wants and likes, we can use them in the present perfect continuous.
For example, we can't say 'I am wanting to talk to him' (present continuous) but we can say:
A particular difficultly for some learners of English can be which tense to choose - the present perfect continuous or present perfect simple.
You can learn more about that here: