Nikon SLR Cameras

My SD card says its full when it's not?

alyssa
alyssa

I've been recording a lot of films with my 16gb SD card lately.
The card was recently full, so I emptied it out on my macbook, deleted the files off the card and put it back in my camera.
It still says full.
So I took it out and replaced it with my old 2 gb card.
there was absolutely NOTHING on the card but there's no memory.

Why is this?

(My camera is a Nikon d3100.)

Monica
Monica

Have you tried turning it off and turning it back on?