As a result of a thousand years of Chinese control, and a further thousand years of strong Chinese influence, a lot of Chinese vocabulary was adopted into Vietnamese. Literary Chinese was used in administration, and thus terms relating to science, politics, education, and philosophy entered the common lexicon. Like and , these terms are pronounced differently in Vietnamese. Over the years, a system establishing rules on how to pronounce Chinese characters was developed.
As contact with the West grew, Western concepts were taken into Vietnamese through the filter of Chinese. Western works were translated into Chinese and read by the literati. Western names, approximated in Chinese , were further garbled in Vietnamese pronunciations. For example, Portugal became , and in Vietnamese ''B? ?ào Nha''. England became ''Anh Cát L?i'' shortened to ''Anh'' , while became ''M? L?i Gia'' , shortened to ''M?'' . Interestingly, ''club'' became ''kurabu'' in Japan, was borrowed to China, then to Vietnam, is read as ''c?u l?c b?'', and abbreviated ''CLB'', which can be an abbreviation for club.
Recently, Sino-Vietnamese has been playing a less important role in Vietnamese as efforts are made to use native Vietnamese words or phonetic pronunciations of certain foreign words in cases where Sino-Vietnamese is considered pointless or simply an elaborate form of phoneticizing. Wherever there exists adequate native Vietnamese terminology, native terms will tend to be used. For example, the White House is referred to as ''Nhà Tr?ng'', as opposed to the austere-sounding ''B?ch ?c'' .
Another example is the Vietnamese name of countries; except for the most deeply ingrained, or ones with Chinese references , Vietnamese names for countries of the world are now close to their original spelling or pronunciation instead of Sino-Vietnamese. However, China-specific names and concepts continue to be rendered in Sino-Vietnamese.
Sometimes regional variation can be found in the prevalence of a Sino-Vietnamese or native term. For example, ''máy bay'' is the standard word for an aeroplane; in the south, ''phi c?'' is more common but losing popularity.
Sino-Vietnamese vocabulary has a status similar to that of Latin-based words in : they are used more in formal context than in everyday life. Because Chinese and Vietnamese use different order for subject and modifier, compound Sino-Vietnamese words or phrases might appear ungrammatical in Vietnamese sentences. For example, the Sino-Vietnamese phrase ''b?ch m?'' can be expressed in Vietnamese as ''ng?a tr?ng'' . For this reason, compound words containing native Vietnamese and Sino-Vietnamese words are very rare.
Some Sino-Vietnamese words are entirely invented by the Vietnamese and are not used in Chinese, such as ''linh m?c'' for pastor. Others are no longer used in modern Chinese or have other meanings. For example, the Vietnamese word ''l? thuy?t'', meaning 'theory', is from the Chinese word 理說, which is no longer in use. The official name for the United States in Vietnamese is ''Hoa K?'' ; it translates somewhat literally to "" is now used in Chinese only as an old word for the American flag and in the name of the American-based Citibank .
Writing Sino-Vietnamese words with ''qu?c ng?'' had caused some confusions about the origins of some terms, due to the large amount of homophones in Chinese and Sino-Vietnamese. For example, both 明 and 冥 are read as ''minh'', thus the word "minh" has two contradictory meanings: ''bright'' and ''dark'' . Perhaps for this reason, the Vietnamese name for Pluto isn't ''Minh V??ng Tinh'' as in other East Asian languages, but is ''Diêm V??ng Tinh'' , named after the and deity . During the Ho Dynasty, Vietnam was officially known as ''??i Ngu'' . Unfortunately, most modern Vietnamese know ''ngu'' as "stupid" ; consequently, some misinterpret it as "Big Idiot" . Conversely, the in South Korea is often erroneously translated as ''s?ng Hàn'' when it should be ''s?ng Hán'' due to the name's similarity with the country name. However, the homograph/homophone problem is not as serious as it appears, because although many Sino-Vietnamese words have multiple meanings when written with ''qu?c ng?'', usually only one has widespread usage, while the others are relegated to obscurity. Furthermore, Sino-Vietnamese words are usually not used alone, but in compound words, thus the meaning of the compound word is preserved even if individually each has multiple meanings.
Most importantly, since ''qu?c ng?'' is an exact phonetic transcription of the spoken language, its understandability is as high as or higher than a normal conversation.
Due to its formality, Sino-Vietnamese words are often preferred when Vietnamese people name their children. Native Vietnamese words are also used in naming, usually in the old days or in rural areas.
*Alves, Mark. "What's so Chinese about Vietnamese?", in Papers from the Ninth Annual Meeting of the Southeast Asian Linguistics Society. University of California, Berkeley. 1999.
*Alves, Mark. "Grammatical Sino-Vietnamese Vocabulary". .
*Wm. C. Hannas . ''Asia's Orthographic Dilemma''. University of Hawaii Press