| Present perfect continuous Present Perfect ContinuousThe Present Perfect Continuous TenseThis tense is used to talk about an action or actions that started in the past and continued until recently or that continue into the future: Present perfect progressiveOr continuous.
Used for unbroken action in the past which continues right up to the present. I have been writing this paper all morning (and still am). Present Perfect Continuous is used for denoting the action which was in progress and has just finished (a) or is still going on (b). For example,
If we have to ask a question with “How long...?” we should use the present perfect continuous. For example,
However, with stative words (such as see, want, like, etc.), or if the situation is considered permanent, we should use the present perfect simple. For example,
If we talk about the whole period, we use “for” and when we talk about the starting point of the action, we use “since”. Source: http://en.wikipedia.org/wiki/Present_perfect_continuous#Present_perfect_progressive |
