Unless you speak Chinese, (Mandarin being the most common as well as the official dialect), it can be difficult to do business in many parts of China without the aid of a translator. English language levels are very patchy and although a layer of fluent English speakers exists, the layer is quite thin and levels fall away very quickly. Communicating in China can, therefore, be a slow, laborious activity and fraught with constant dangers in terms of misunderstanding and mistranslation. Don't assume comprehension. Cover the same ground several times and constantly check for understanding.
One of the reasons that communication can be such a problem in China is that along with many other Asians, the Chinese find it extremely difficult to say 'no'. Saying 'no' causes both embarrassment and loss of face and it is therefore better to agree with things in a less than direct manner. Thus anything other than an unequivocal 'yes' probably means 'no'. Be very wary of phrases such as 'Yes but it might be difficult' and 'Yes, probably'.
It is also difficult to deliver bad news and this is often done through the use of an intermediary who can soften the blow and try to preserve as much good-will within the relationship as possible.
The Chinese have a reputation for 'impassiveness' and this is largely based on Western misinterpretation of Chinese body language. As with the Japanese, the Chinese use a very limited amount of visual body language and Westerners interpret this rigidity as a lack of responsiveness and emotion. Lack of overt body language does not mean that the Chinese do not show their reactions - more that westerners are not skilled at reading it across the cultural divide.
Finally, don't always assume that just because somebody happens to speak 'good' English that they will automatically more competent than soembody who doesnt. Unles frequent interface into the West is tantamount, fluency in English should be seen as an added extra.