Standard Chinese, also known as Mandarin, Putonghua and Guoyu, is a standardized variety of Chinese. It is the sole official language of both the People's Republic of China and the Republic of China; it is also one of the four official languages of Singapore. The phonology of the standard is based on the Beijing dialect, but its vocabulary is drawn from the large and diverse group of Mandarin varieties spoken across northern, central, and southwestern China. The grammar is standardized to the body of modern literary works that define written vernacular Chinese, the colloquial alternative to Classical Chinese developed around the turn of the 20th century.Like other varieties of Chinese, Standard Chinese is a tonal language. It has more initial consonants but fewer vowels, final consonants and tones than southern varieties. Standard Chinese is an analytic language, though with many compound words. Like other varieties of Chinese it is a topic-prominent language, and has subject–verb–object word order. The language is usually written using Chinese characters, in either simplified or traditional form, augmented by Hanyu Pinyin romanization for pedagogical purposes.