hasn't seen anything
On a regardé par la fenêtre, mais on n'a rien vu.
We looked out the window, but we didn’t see anything.
Même Dumbledore n'a rien vu venir.
Even Dumbledore didn't see it coming.
— Harry Potter et l'Ordre du Phénix (2007)
Marie n'a rien vu.
Marie didn’t see anything.
She didn't see anything.