汉字很难， 发音最难。

我喜欢学习汉语 :)

Well, I assume you are referring to Mandarin Chinese -

Written: There's two sets of written Chinese currently in use: simplified and traditional. You can't necessarily know the exact pronunciation of a word like you do in English if you haven't seen it before.

Spoken: Chinese has 4 tones (5 with neutral tone) as it's a tonal language. You don't indicate the tones in the hanzi, just the pinyin (which aides in pronunciation).

I hope this answers your question.