As a Chinese, I can tell you that there are only 3000 common Chinese characters. My nephew begin to read news paper at grade 4 ( 10 years old). I begin to read very complicate novels at 13. A good thing about Chinese character is: I can easily read laws if I want, because there is not much new vocabulary to read. Tone is not a problem for baby. They can grasp it from day one when they start to speak.( I have 3 kids) There is a lot logic inside Chinese characters.