A very good question ! its hard to say .First As to spoken language. And i think it sholdn't exist any difficulties for a Chinese to speak his/her mother tone. If i may ask "do you have problems with your spoken English ". and i think you will give me negative answer. so i do not think there are any difficulties when Chinese speak their own language second it is definetely different between a Chinese and a foreigner to study Chinese.if you do not want to read 《红楼梦》or 《三国演义》(classical Chinese literature) in depth and you just want to talk with a native . So its ok and it should be much easier . As for Chinese themselves different indiviual have their own difficulties with their written Chinese ,and i think the most frequency difficulties we meet is allcation" how to use words together to make a sentence laconic".

for chinese, we can hear each other, but maybe we can not understand each other, because we can't know the real meaning behind our sentences if we grow up in families with very different culture. Then a Chinese without good education experience can not give out a well orgnized paper. even the educated, can't work out a satisfied one. chinese from the very south and the very north with their own dialects can not understand each other at all. for foreigners, at beginning, the four tones and pin yin like zh-ch-sh, j-q-x, z-c-s are difficult. Then with the time of learning, one charactor with several meanings, one pronounciation with some different charactors, sayings, proverbs and useful expressions are difficult.

Growing the rare word and word not always seen either will not be read. I am a Chinese, but my regular meeting meets this kind of question.

the above-mentioned answer in quite good.But I think there also may be some problems with our spoken chinese.one big problem is different dialects.this is not severe as you just talk with some people surrounding.the other one is there're many different Chinese words which have th same pronunciation.It may be a big problem when you just begin to speak chinese.by all means ,Chinese is so wonderful that as a chinese i love it so much. I wish that you will get great fun from it.

My friend, though some of the answers above are correct in some ways, they are not completely honest. There is a HUGE problem with Chinese people from "the countryside" (which I don't like to call it but they do so....) and less educated Chinese people who can ONLY speak their own dialect or sometimes a very BAD version of the standard Mandarin. I'm from the UK, it is small and we also have dialects, different people from different places have different words that others don't use or understand when heard (unless the context is obvious). Now imagine if you stretched the UK to the size of China! Dialects become more in number, accents change more, more words enter the scope and before you know it, you have a problem. For example, I used to live in a big province called An Hui. I can speak one dialect from there but ONLY with people from that small city where I stayed. If I go anywhere else in An Hui they wouldn't understand me. Sad but true, if you study Mandarin long enough you can have a much better handle on it than a large portion of Chinese people! Especially the older generation. In HK and maybe Guang Zhou too I know that alot of them can't even speak Mandarin at all! they only speak their dialect (the most commonly known, Cantonese). I learnt all my Shanghainese and An Hui dialect from my friends and their parents whose Mandarin lacked and so had to speak their dialect to me!!