Present perfect progressive

A close relative of the present perfect, the present perfect progressive, emphasizes the continuation of a single action: it indicates that the action is ongoing or continuing at the moment one is speaking. The form — relatively complicated — consists of the past auxiliary "to have" + "been" (the past participle of "to be") + the present participle of the principal verb. For example:

• I have been trying to reach you all afternoon.
• They have been working hard to finish their project.