The progressive form is not normally used with punctual verbs such as start, stop, finish, which refer to actions that are completed at a single point in time;

The progressive form is often used for events which started in the past and are still continuing, or which have stopped, but whose effects are still continuing;

The difference between the present perfect simple and the present perfect progressive may sometimes be between an emphasis on the event itself as a progressive, extended activity (progressive form), compared with the results of the event, or some other, secondary reference to the event (simple form);

Both forms may refer to completed events;

The progressive form of the present perfect can emphasise completion of an event when used with verbs denoting actions or events.