It's Levi-O-sa, not Leviusa!
Hermione is, in the words of Snape, an insufferable know-it-all. Which is right, but a bit harsh. She likes to learn and, unlike the majority of the other students at Hogwarts School of Witchcraft and Wizardry, she actually knew things before she came to the school.
She is constantly fixing Harry's glasses, curing Ron of some backfiring curse and trying to find the solutions to life's many problems such as, why is there a noseless egghead chasing after me and my friends.
She plays a pivotal role in the fight against Voldy, and she is often the one to find the answers to things. However, she isn't too good at riding a broomstick and she can't see the future.