Have you or anyone you know
1. ...ever experienced a prophesy (vision or dream) that came true?
Sadly, when I do dream I usually dream of things to come.
2. ...dreamed of a stranger, then actually met them later?
Repeat of number one.
3. ...seen a wonder in heaven? (including UFO's)
I have seen(and with others) items that are hard to explain scientifically in the night skies.
4. ...seen a "sign" on the earth?
I am not sure how to answer this question.
5. ...experienced knowledge of another language without ever having studied it?
No, not that I am aware.