The Han people have their own spoken and written languages, namely Chinese. It is the most commonly used language in China, and one of the most commonly used languages in the world. All China's 55 minority peoples have their own languages except the Hui and Manchu, who use Chinese; 21 minorities have their own scripts, in which 27 languages are written. Classes in schools in predominantly national minority areas are taught in the local language, using local-language textbooks, as well as in Putonghua or Mandarin — the official national standard spoken language of China, based on the principal dialect spoken in and around Beijing.