I Sprained My Ankle Wednesday Night. The Er Doctor Was

I sprained my ankle Wednesday night. The er Doctor was shocked it was not broken. I was wondering if I had a ruptured ligament how I would tell? It was the size of a baseball and the bruises spread all across my foot and up my ankle. I can walk on it still because of the pain. Also it feels off. Can you tell me what would be different if I had I grade 3 full tear?