The culture of Vietnam (, chữ Nôm: 文化越南) are the customs and traditions of the major Kinh people and the other ethnic groups of Vietnam. Vietnam is part of the Sinosphere, also known as the East Asian cultural sphere due to the influence of Chinese culture on Vietnamese culture, as well as part of Southeast Asia. Ancient Vietnamese cultural artifacts, such as Dong Son drums were found spread throughout Southeast Asia and South China, suggesting a spread of ancient Viet (Yue) culture all the way south to Indonesia. Vietnamese culture was heavily influenced by Chinese culture due to the "1000 years of Northern Rule". During this period and until the 19th century, Classical Chinese (Hán văn) was the language used for formal writing. Between the 15th and 19th centuries, popular literature and folk songs were written in the Vietnamese language using a Vietnamese script (chữ Nôm) derived from Chinese characters (chữ Hán). Following independence from China in the 10th century, Vietnam began a southward expansion and annexed territories formerly belonging to Champa and Khmer, resulting in various influences on the Vietnamese. During the French colonial period, Catholicism, and a Latin script romanizing the Vietnamese language, the Vietnamese alphabet (), were introduced in Vietnam. Some elements considered to be characteristic of Vietnamese culture include ancestor veneration, respect for community and family, and living in harmony with nature. Language Vietnam is one of the most linguistic diverse countries in Southeast Asia. Although Vietnamese is set as the official language of Vietnam, there are currently more than 100 speaking languages in the country. They belong to five different major linguistic families: Austronesian, Austroasiatic, Hmong–Mien, Sino–Tibetan, and Kra–Dai. The Vietnamese language contains a large body of Sino-Vietnamese vocabulary. The Vietnamese language is an Austroasiatic language with monosyllabic and tonal features, sharing similarities with some Northern Austroasiatic languages, such as Bolyu. The writing of Vietnamese started with Vietnamese script (chữ Nôm) in the 13th century which used Chinese script as a basis, to the current Latin iteration (chữ Quốc Ngữ). The current Vietnamese alphabet uses diacritics (glyph added to a letter) to represent tones in Vietnamese writing. When computerised, digraphs are used. For example, input 'a' generates 'a', but input 'aa' generates â. The Vietnamese Latin alphabet uses the horn for the letters "ơ" and "ư"; the circumflex for the letters "â", "ê", and "ô"; the breve for the letter "ă"; and a bar through