  Harry had learned and taught them the Disarming Spell, which would more than likely prove vital. Ron had learned and taught the Jelly Legs spells, it was hilarious using that one on a fourth year arrogant Ravenclaw. Hermione had learned the Tripping Spell, another good spell when trying to disarm someone or taking down arrogant people. She had also learned the Stinging Hex which she demonstrated on a Gryffindor that had been bullying Tracy Davies.