Throughout the series, Harry Potter is described as a gifted wizard apprentice. He has a particular talent for flying, which manifests itself in Harry Potter and the Philosopher's Stone the first time he tries it, and gets him a place on a Quidditch team one year before the normal minimum joining age. He captains it in his sixth year. In his fourth year (Harry Potter and the Goblet of Fire), Harry is able to confront a dragon on his broomstick.
Harry is also gifted in Defence Against the Dark Arts, in which he becomes proficient due to his repeated encounters with Voldemort and various monsters. In his third year, Harry becomes able to cast the very advanced Patronus Charm, and by his fifth year he has become so talented at the subject that he is able to teach his fellow students in Dumbledore's Army, some even older than him how to defend themselves against Dark Magic. At the end of that year, he achieves an 'Outstanding' Defence Against the Dark Arts O.W.L., something that not even Hermione achieved. He is a skilled duellist, the only one of the six Dumbledore's Army members to be neither injured nor incapacitated during the battle with Death Eaters in the Department of Mysteries in Harry Potter and the Order of the Phoenix. He also fends off numerous Death Eaters during his flight to the Burrow at the beginning of Harry Potter and the Deathly Hallows.
Harry also has the unusual ability to speak and understand "Parseltongue", a language associated with Dark Magic. This, it transpires, is because he harbours a piece of Voldemort's soul. He loses this ability after the part of Voldemort's soul inside him is destroyed at the end of The Deathly Hallows.