DROP or PENDANT EARS look kind of different in different breeds. This sort of ear hangs down from the spot where it is attached to the side of the dog's head. Sometimes these ears make a full drop, and sometimes they are folded. So Basset Hounds and Skye Terriers both have drop ears, even though they don't look very much alike.
FILBERT-SHAPED EARS are mostly only found in Bedlington Terriers. Supposedly their ears are shaped like filbert nuts, but they don't look much like filberts if you ask me.
FOLDED EARS or ROLLED EARS are long, pendant ears that sort of fold over along the edges. Bloodhounds and Field Spaniels have ears like this.
PRICK or ERECT EARS stand up stiffly. They might be this way naturally, or they might stand up because they were cropped. Examples of breeds with prick ears are German Shepherds and Pomeranians. But one thing that's confusing to me is that when you look at a German Shepherd from the side, the ears look pretty much hooded, like a basenji's, so I'm not sure why they are called "prick ears" and not "hooded ears."
Well, that's pretty much all the ear shapes I could find names for. Now you just need to study them, and we will have a quiz tomorrow!