1. The result, the experience; it's used for emphasising a number, not a duration.
2. The main key point is that it's used when we have some conjunction, I mean the connection between the past action or may be event with the present time.
3. Inspite of the fact that Present Perfect Continuos has some kind of incompleteness, the Present Perfect gives us clear meaning, understanding of the result and so forth.
This is not completed list of the cases the Present Perfect goes well with, the cases it is used in. Although I've got some experience learning English and diving itno the details of different grammar aspects, I'm sorry if something isn't listed or described in an incorrect manner, because of my not-native oigin.
There were a lot topics dedicated to this question. I've created many similar to them.
That was a little entry. Having made a lot of researches, I found the anologs of different grammar points, e.g. Gerund. However, I faced with little problem I mean the moments appearing when we're translating sentences into English. Would you mind taking look at the following example from my another topic "Is everything ok (using Present Perfect in the peculiar context)?":
A: Oh, I've forgotten the money at home.
B: Don't worry. I'll lend you it.
There were link called "Fumble Fingers' Truism", but I still don't fully understand it. One of the comments was:
"The perfect makes perfect sense (!) in "Oh, I've gone and forgotten my wallet!" or in your example. Both of our examples satisfy the truism—we do have to use it to express the thought (or comport with the idiom). In the OP's example, it's not needed, and in common speech the thought wouldn't be expressed as he has it."
I would be very greatful greatful, if you given me more detailed comments on the "ambiguous", as I think, moments in bold. It would be kind of you to provide me with another examples.
I want to understand it clear and moreover I think this topic will be of help to everyone being in a dire straits, translating their thoughts into English and it doesn't matter if it's a simple conversation or translating an academic article.