Most Chinese students have a same problem about English learning. If you are a native English foreigner,they can write something you understand. They can read a passage or a note that you give them,yet they can't communicate with you verbally. It's a common problem in China because most of students learning English from textbooks. They can write a credible piece of English prose. And respond a correspondence with little or no difficulty. However, if you give them a phone call, they will feel totally helpless .They can grasp with only a few auditory symbols, the words sounds.