present perfect simple and continuous

We said that the perfect aspect is used whenever there is a connection between two points in time.

Today we are focusing on present perfect simple and continuous, which suggest that a past action or state is still connected to the present.

We've painted the bedroom. (We painted the bedroom in the past and now the result can be seen.)

They have been waiting for hours. (The action of "waiting" started some hours ago and the people are still waiting now.)

We use the present perfect simple with action verbs to emphasize the completion of an event in the recent past.

I’ve written the Politics essay. (Completed event.)

We use the present perfect continuous to talk about ongoing events or activities which started at a time in the past and are still continuing up until now.

I’ve been writing the Politics essay. (Ongoing activity: I’m still writing it.)

Sometimes we can use either form and the meaning is the same:

I’ve lived here for 20 years.

I’ve been living here for 20 years.

The present perfect continuous form is not normally used with verbs that refer to actions that are completed at a single point in time such as start, stop, finish:

Has the concert started already?

Not: Has the concert been starting already?