Black Star Won't Fill?

[Scarecrow222]

I did the azuras star quest and got the black soul gem. It won't fill though. I know it only captures human souls but I've killed about 75 imperials, a hunter, and a couple of red guards and regular citizens. When I go to the black star in my inventory, it still says empty.
P.S. when I kill humans it doesn't even say black star filled or soul gem filled either. Please help

 

[Rayven]

Are you using a Soul Trap enchanted weapon or the spell itself when you're killing things?

 

[Scarecrow222]

..... I didn't know I had to with the black star... Lol thanks