We have 26. Their words are spoken in four different tones that can completely alter the meaning. Then there are the people. China has the world's largest population. In China there are 1.3 billion people crowded into an area about the same size as the United States.
Food is another challenge.
I landed in China expecting menus similar to Chinese restaurants in the United States. Chow Mein, Egg Foo Yong and fortune cookies never appear in Chinese restaurants. Instead, you get things like dog meat, plump cicada larvae served like shrimp cocktails, and stewed cow stomach. Yesterday I picked up a dish of delicious-looking chicken fingers. They turned out to be chicken toes, claws and all.