WE USE PRESENT PERFECT...
SOMETIMES because it is related to now,
sometimes because THERE IS NO EXACTNESS...
So, it depends on the case!
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take a look at these examples below:
Let's imagine this answer: "Yes, I have..."
Well, she is not seeing it now, is she? Not anymore...
She saw it in the past, and, because IT DOESN'T MATTER EXACTLY WHEN,
she uses the Present Perfect instead of the Past Simple...
Well, she is not seeing it now, is she? Not anymore...
She saw it in the past, and, because IT DOESN'T MATTER EXACTLY WHEN,
she uses the Present Perfect instead of the Past Simple...
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another example
THERE IS NO PRECISION, NO ACCURACY...