Sometimes the present perfect continuous tense has the same meaning as the present perfect tense, and it makes me feel confused. I don't know which one is the better to use. For example:
- Someone has eaten my chips.
- Someone has been eating my chips.
The present perfect is called "perfect" because the action is complete. Sometime in the past, some hungry and impolite person finished off your snack.
A continuous (or progressive) tense indicates an action spread out over time. In the case of the present perfect continuous, the ongoing action was ongoing in the past. So sometime over a past interval some hungry and impolite person helped himself to your snack. But at least there might be some chips left. If there are, you'll have to be careful to watch them because the pilfering might still continue.
A good question. Someone has eaten my chips: perfect for fact. ( Someone is surprised that his chips are gone.) Someone has been eating my chips. In this case it has exactly the same meaning, but is has much more weight. This is no case of perfect/perfect continuous for action over a time span up to now.
Perfect can be used for news, for fact, and for continuous action over a time span up to now. The context and the situation decides which case it is.