Simple; Descriptive
Alanna experiences most of the action in the book, so even though she's not technically the narrator (check out our "Narrator Point-of-View" section for more on this), we're going to talk a lot about how the world looks through her eyes.
Unlike some of the other kids her age, Alanna can read and write—but that doesn't mean she's poetic and artistically expressive. She tends to be simple and to the point with the way she describes things, such as when she first meets her sponsor:
Duke Gareth of Naxen was tall and thin, with dull brown hair that fell into his muddy brown eyes. Though he was plain looking, there was something commanding about him all the same. (2.1)
Sure, it's not the most exciting writing style ever, but it gets the job done: we have a mental image of Duke Gareth. We get these little pictures a lot. Alanna takes an interest in the world around her, so whenever she goes somewhere new or meets someone new, we tend to get a description. Plus, she's observant enough to give us a decent level of detail. For example, when Alanna goes to Mistress Cooper with her lady-business problems, she enters a small, clean room: "Healing plants of all kinds hung from the rafters, giving the room a fragrant smell. A small wooden table covered with a clean sheet sat in the room's center" (6.30). Thanks to Alanna's description, we have a good sense of where she is and what kind of care she'll receive.
The simple, direct style in which the story is told makes it easy for us to tag along and form a mental image of Alanna's various adventures and trials. Which is pretty neat, since we don't get to train to become knights or use magic swords on a daily basis.