English: This video explores the usages of the Present Perfect Continuous -- the tense that relates past activities to the present. It implies that the activity is likely to continue in the future or that the activity was in progress for some length of time, or both.

The first usage is to talk about an incomplete and ongoing activity, when we want to say how long it has continued. For example, "I have been teaching for ten years." It talks about an action that started in the past and is continuing now.

The second usage is to describe recently finished activities that have present results. For example, "He is tired because he has been chopping trees." It is talking about an action that was continuing until very recently. The Present Perfect Continuous emphasizes the action or the activity not the result or the completed action.