Twilight possesses a huge amount of book-knowledge and intelligence. But Twilight lacks in social skills. This can be seen right in the first episode/pilot when some ponies invite her to a "get together" but Twilight would rather study. Later then, Twilight Sparkle is sent to Ponyville by Celestia to make some friends. Twilight Sparkle feels the opposite way, and doesn't really care to make new friends. While there, Twilight still devotes herself to studying and not trying to make friends. Though, she does meet the rest of the main ponies. Later in the episode Pinkie Pie even holds a party for Twilight, but Twilight isn't interested and just goes to bed. Twilight studied about the "Mare in the Moon" and the "Elements of Harmony" and learned that Nightmare Moon was going to come back for revenge. Twilight thought she could defeat Nightmare Moon by herself, but realizes after everything her "friends" have done for her, she realizes that she does need them to defeat Nightmare Moon. Without her friends would of never defeated Nightmare Moon or survived going through the Everfree Forest.

Twilight can seem worldly and naive because of the lack of her social skills, which can be demonstrated when she had her first slumber party with Applejack and Rarity in the episode Look Before You Sleep she was really excited about it, since she used a book about slumber parties through the episode, and checked off stuff as they completed them. When a tree came through her bedroom window, she was at a loss because she couldn't find it in the book. She also ran her first long-distance running event in the episode Fall Weather Friends, but she only had to read about it and not take the book along. She ended up getting fifth because she did what the book said and paced herself.

She is also the most educated out of all her friends, and tends to take more practical approaches to solving problems. She is also straightforward and honest, she is prone to her friends sarcasm. She never wants to show off her powers to her, even though she has incredible magical powers and is highly intelligent. Despite her not wanting to make friends from the start, she realizes she really treasures her friends.

Later in the show you are given the knowledge that she has a brother named Shining Armor. They according to her were really close and was her one of her only friends when living in Canterlot. She ends up gathering some of her personality from their relationship back then and retains some aspects of it throughout the show.

She is also organized, which can seen a lot throughout the series.

So try to sound exactly like her from the show.