I recommend keeping three basic uses of the Present Perfect in mind:
- Life Experience
- Change in Situation (in which the change is relevant to the present)
- Up to Now
- Life Experience (sometimes used with "ever" and "never")
Have you ever been to Pluto?
No, but I've been to the toilet.
- Change in Situation (sometimes used with "just" and "already")
Call a doctor! I've just cut off my ears!
Don't call the doctor. I've already sewn his ears back on.
Note that this doesn't have to be a fast change or a recent change. We can use it like this:
The Earth is a crazy place because life has evolved here.
The important idea is that a change has led to the present situation, like something casting a shadow.
- Up to Now (sometimes used with "yet")
You've had that hat on for five days, but you still haven't put on your pants.
Have you spray painted some pants onto him yet?
You can use two or three of these together, too.
It's his first day of school and he hasn't learned to speak yet, so the teachers are disappointed.
The above example talks about Life Experience, Up to Now, and even a Change in Situation.
Other uses of Perfect tenses are generally used for the same reasons.
For example, here are examples related to the ones above, for the same three uses (Life Experience, Change in Situation, and Up to Now):
When you went to Pluto, had you ever been there before? Or had you only been to the toilet?
(For this Change in Situation example, I'll use Reported Speech / Indirect Speech.)
Marge told me to call a doctor, because she'd just cut her ears off. But Hector told me not to call the doctor, because he'd already sewn her hears back on.
Hector is really amazing.
Let me also address the Earth example:
The Earth was a really crazy place before Ming destroyed it, because life had evolved there.
Last, but not least:
Charles had worn that very tall hat for five days and hadn't put on his pants. Had Susie spray painted pants onto him yet? No, she hadn't, but she had been thinking about it...
This leads into one last point I'll address in brief (because it's a larger topic), which is adding in the Continuous tense, the "-ing" tense. This means that we use a form of be plus the Present Participle (the "-ing" form).
If we use a Perfect Continuous tense, we use "has/have been" + VERBing.
If you have been paying attention, you may now be interested to know how this is different.
In general, the Continuous aspect indicates that a verb is active now and not complete within the time we're describing. We may use it to emphasize that the verb is temporary, to indicate that it's something in progress (from one state to another), to convey repetition, and/or to emphasize activity.
Rather than give more rules, I will leave you with a few examples with some context suggesting what additional information the Continuous aspect conveys. This is not absolutely complete, but is plenty to be useful.
Last year my friend invited me to move to Mars with her. I'd never lived on Mars before, so I'd been hearing good things on the news about it and I decided to give it a try. I'd lived on Earth all my life, and for two weeks I had been living with my parents, so I was ready to move. By the time we finally reached Mars, we'd been flying for two weeks. (Years ago it took much longer to reach Mars, but a new startup had been studying antimatter fuels and had invented a much faster rocket.) Soon after we'd arrived, I started to wonder why I'd been looking forward to the trip so much...
"I'd been hearing" suggests repetition. "I'd been living" suggests that the living arrangement was temporary, and subtly suggests that the speaker had been hoping to leave, rather than stay for years.