I'm working on my first novel, and the main problem I've had with writing is the characters' personalities. Each character has a unique personality, but when I write it seems to change. Quickly. Their dialect, sense of humor, rudeness, and so on, are constantly changing. I keep having to go back and change scenes, over and over again. Does anybody else have difficulty with this? Or does anybody have any advice as to how I can overcome this problem? In advance, thank you!