Putonghua refers to Modern Standard Chinese, or simply Modern Chinese. It is the common language of the Han nationality "with its pronunciation based on the Beijing dialect, with China's northern dialects as its basic dialect, and its grammar based on the model of modern vernacular writings." Putonghua is both the spoken and written language of Modern Chinese. The term is also known as Mandarin or Chinese. It is a common language used on the Chinese mainland, in Hong Kong, Macao, Taiwan and Chinese abroad. Putonghua is China's official language, and one of Singapore's four official languages. It is also one of the United Nations' six major official languages.