For sure. How many are there, 4? Flame, frost, and storm atronahcs, and the dog... the familiar. There's also the staff that can summon up a badass daedra for 60 seconds. Are there any more than that? Oh yeah, that asssassin ghost who's really cool for about 5 minutes. Then he never shuts up and becomes like an annoying relative who's death is quietly welcomed. After a while I kept expecting him to start complaining that I never talk to him and only call him when I want something.
Flame, Frost, Shock, Daedra, Dog, Flaming Dog, The Assassin Ghost, The shade of a mage whose experiment went wrong or did it?
So eight different summons you can learn.