The language spoken in Beijing is often referred to as Mandarin or Putonghua. Putonghua, which means "common language", is the country's predominant language and is widely used by more than 70 percent of the population. Putonghua is variously referred to as the "Han language" (hanyu), "Mandarin", or simply Chinese. About two-thirds of the Han people are native speakers of Putonghua, while Han people who come from the southwestern and southeastern sections of China often speak Putonghua as well as their own dialects, such as Shanghaiese and Cantonese.
Various groups such as the Mongolian, Tibetan, Naxi, Yi, Uygur, as well as many other ethnic groups have their own "native" languages. Because of the increased economic and cultural flow across China during the past twenty years, the use of Putonghua has also increased.
In recent years, as tourism to China has been increasing, the use of English has been sweeping across the country. Most of the service staff in hotels and many stores can speak fluent or basic English. Now, there is no longer any reason to have language concerns when visiting China. Of course, it will be interesting and fun for you to learn some basic Putonghua.