Sofia and Ariel speak properly and elegantly. They never use any type of slang. If you want to talk like a princess, you'll need to speak clearly in a proper tone.
A princess has proper posture. You should stand up straight, and you should never slouch. If you always slouch, you can correct this by walking with a book on your head.
In order to act like a princess, you'll need to make smart choices. For example, school should always be a top priority.
A princess helps others. You can be kind by sharing and by doing your chores for no rewards.