Yzranth's daily pattern changed once he discovered the library. He would get fed before Hannah went to work, head to the library to practice reading, come home and be fed again, and then spend the evenings freely wandering her dwelling (that he later found out was called an apartment) until she went to bed and put him back in the tank.
It wasn't what he had expected out of finding himself a princess but when in the human world, he had to do what the humans expected. Talking to her in lizard form would frighten her.
He did want to talk to her though. He loved listening to her talk but he wanted to be able to talk back and tell her what he thought about the things she said.
He was satisfied enough with the way things were until the pattern changed. Nearly every night, she came home, fed him, got changed, and then left again so he was stuck in the tank. He didn't like that.