Sino-Vietnamese vocabulary ( (), Chữ Hán: 詞漢越, 'Chinese-Vietnamese words') is a layer of about 3,000 monosyllabic morphemes of the Vietnamese language borrowed from Literary Chinese with consistent pronunciations based on Middle Chinese. Compounds using these morphemes are used extensively in cultural and technical vocabulary. Together with Sino-Korean and Sino-Japanese vocabularies, Sino-Vietnamese has been used in the reconstruction of the sound categories of Middle Chinese. Samuel Martin grouped the three together as "Sino-Xenic". There is also an Old Sino-Vietnamese layer consisting of a few hundred words borrowed individually from Chinese in earlier periods, which are treated by speakers as native words. More recent loans from southern Chinese languages, usually names of foodstuffs such as 'Chinese sausage' (from Cantonese ), are not treated as Sino-Vietnamese but more direct borrowings.

Estimates of the proportion of words of Sinitic origin in the Vietnamese lexicon vary from one third to half and even to 70%. The proportion tends towards the lower end in speech and towards the higher end in technical writing. In the famous dictionary by Vietnamese linguist , about 40% of the vocabulary is of Sinitic origin.

Monosyllabic loanwords

As a result of a thousand years of Chinese control, a small number of Sinitic words were borrowed into Vietnamese, called Old Sino-Vietnamese layer. Furthermore, a thousand years of use of Literary Chinese after independence, a considerable number of Sinitic words were borrowed, called the Sino-Vietnamese layer. These layers were first systematically studied by linguist Wang Li.

The ancestor of the Vietic languages was atonal and sesquisyllabic, featured many consonant clusters, and made use of affixes. The northern Vietic varieties ancestral to Vietnamese and Muong have long been in contact with Tai languages and Chinese as part of a zone of convergence known as the Mainland Southeast Asia linguistic area. As a result, most languages of this area, including Middle Chinese and Vietnamese, are analytic, with almost all morphemes monosyllabic and lacking inflection. The phonological structure of their syllables is also similar. Traces of the original consonant clusters can be found in materials from the 17th century, but have disappeared from modern Vietnamese.

The Old Sino-Vietnamese layer was introduced after the Chinese conquest of the kingdom of Nanyue, including the northern part of Vietnam, in 111 BC. The influence of the Chinese language was particularly felt during the Eastern Han period (25–190 AD), due to increased Chinese immigration and official efforts to sinicize the territory. This layer consists of roughly 400 words, which have been fully assimilated and are treated by Vietnamese speakers as native words. It has also been theorised that some Old-Sino-Vietnamese words came from a language shift from a population of Annamese Middle Chinese speakers that lived in the Red River Delta, in northern Vietnam, to proto-Viet-Muong.

The much more extensive Sino-Vietnamese proper was introduced with Chinese rhyme dictionaries such as the Qieyun in the late Tang dynasty (618–907). Vietnamese scholars used a systematic rendering of Middle Chinese within the phonology of Vietnamese to derive consistent pronunciations for the entire Chinese lexicon. After driving out the Chinese in 880, the Vietnamese sought to build a state on the Chinese model, using Literary Chinese for all formal writing, including administration and scholarship, until the early 20th century. Around 3,000 words entered Vietnamese over this period. Some of these were re-introductions of words borrowed at the Old Sino-Vietnamese stage, with different pronunciations due to intervening sound changes in Vietnamese and Chinese, and often with a shift in meaning.

+ Examples of multiple-borrowed Sinitic words Chinese(Old > Middle) Old Sino-Vietnamese Sino-Vietnamese *mjəts > mjɨjH mùi [mùj] 'smell, odor' vị [vǐˀ] 'flavor, taste' *pənʔ > pwonX vốn [vǒn] 'capital, funds' bản [ɓân] 'root, foundation' *wjek > ywek việc [viə̌ˀk] 'work, event' dịch [zǐˀc] 'service, corvee' *muks > mawH mũ [mǔˀ] 'hat' mạo [mâˀw] 'hat' *gre > hɛ giày [ʑàːj] 'shoe' hài [hàːj] 'shoe' *kras > kæH gả [ɣǎˀ] 'marry' giá [zǎː] 'marry' *bjəʔ > bjuwX vợ [vɤ̂ʔ] 'wife' phụ [fûˀ] 'woman' *gjojʔ > gjweX cúi [kǔj] 'bow, prostrate oneself' quỳ [kɥì] 'kneel' *rijʔ > lejX lạy [lâˀj] 'kowtow' lễ [lěˀ] 'ceremony' *pjap > pjop phép [fɛ̌p] 'rule, law' pháp [fǎːp] 'rule, law'

Wang Li followed Henri Maspero in identifying a problematic group of forms with "softened" initials g-, gi, d- and v- as Sino-Vietnamese loans that had been affected by changes in colloquial Vietnamese. Most scholars now follow André-Georges Haudricourt in assigning these words to the Old Sino-Vietnamese layer.

Sino-Vietnamese shows a number of distinctive developments from Middle Chinese: Sino-Vietnamese distinguishes Early Middle Chinese palatal and retroflex sibilants, which are identified in all modern Chinese languages, and had already merged by the Late Middle Chinese period. Sino-Vietnamese reflects Late Middle Chinese labiodental initials, which were not distinguished from labial stops at the Early Middle Chinese phase. Middle Chinese grade II finals yield a palatal medial -y- like northern Chinese languages but unlike southern ones. For example, Middle Chinese kæw yields SV , Cantonese gaau and Beijing .

Modern compounds Up until the early 20th century, Literary Chinese was the vehicle of administration and scholarship, not only in China, but also in Vietnam, Korea and Japan, similar to Latin in medieval Europe. Though not a spoken language, this shared written language was read aloud in different places according to local traditions derived from Middle Chinese pronunciation: the literary readings in various parts of China and Sino-Xenic pronunciations in the other countries.

As contact with the West grew, Western works were translated into Literary Chinese and read by the literate. In order to translate words for new concepts (political, religious, scientific, medical and technical terminology) scholars in these countries coined new compounds formed from Chinese morphemes and written with Chinese characters. The local readings of these compounds were readily adopted into the respective local vernaculars of Japan, Korea and Vietnam. For example, the Chinese mathematician Li Shanlan created hundreds of translations of mathematical terms, including ('replace-number-study') for 'algebra', yielding modern Mandarin dàishùxué, Vietnamese đại số học, Japanese daisūgaku and Korean daesuhak. Often, multiple compounds for the same concept were in circulation for some time before a winner emerged, with the final choice sometimes differing between countries.

A fairly large amount of Sino-Vietnamese compounds have meanings that differ significantly from their usage in other Sinitic vocabularies. For example: bác sĩ () is widely used with the meaning 'physician' or 'medical doctor', while in Mandarin it refers to a doctoral degree; tiến sĩ (進士) is used to refer to 'doctoral degree', whilst in Mandarin it is used to refer to 'successful candidate in the highest imperial civil service examination'. bạc 'silver' is the Old Sino-Vietnamese reflex of Old Chinese *bra:g 'white', cognate with later Sino-Vietnamese bạch 'white' and Non-Sino-Vietnamese bệch '(of complexion) chalky', yet in Mandarin means 'thin sheet of metal' (variants: , ) and 鉑 (pinyin: bó) has also acquired the meaning 'platinum', whose Sino-Vietnamese name is bạch kim, literally 'white gold'; luyện kim () means 'metallurgy' instead of its original meaning, 'alchemy'; giáo sư () means 'teacher' in Mandarin, but is now associated with 'professor' in Vietnamese. English "club" became kurabu in Japan, was borrowed to China, then to Vietnam, is read as câu lạc bộ, and abbreviated CLB, which can be an abbreviation for club. linh miêu () means 'civet' in Mandarin but means 'lynx' in Vietnamese. ân nghĩa ~ ơn nghĩa () not only retains its original Sinitic meaning "feeling of gratitude"Ban Gu (author), Tjan Tjoe Som (translator) (1949). Po Hu T'ung - The Comprehensive Discussions in the White Tiger Hall, Volume II. Leiden: Brill. p. 457. translation: "A son has the right to avenge his father because he has the same duty towards him as the subject towards his Lord. Neither a faithful subject nor a filial son can ever be resigned [to the murder of his Lord or father], for his feelings of gratitude and obligation cannot be taken away from him." Chinese original:「子得為父報仇者,臣子於君父,其義一也。忠臣孝子所以不能已,以恩義不可奪也。」"ân nghĩa" in Hồ Ngọc Đức's Vietnamese dictionary but also acquires the extended meaning "favor, kindness"."ân nghĩa" in bab.la thời tiết (時節) is used with the meaning of 'weather", while in Mandarin, it means a 'season' (mainly refers to a specific period of time, often within the context of a particular season). thư viện (書院) means 'library' in Vietnamese, but in Mandarin, it refers to a 'study room' or an 'academy'. phương phi (芳菲) is an adjective meaning 'fat' or 'corpulent', but in Mandarin, it means 'fragrant' or 'fresh-smelling'. ung thư (癰疽) means 'cancer' in Vietnamese, but in Mandarin, it is a term used in traditional Chinese medicine meaning a 'skin abscess'. thập phân (十分) means 'decimal' in Vietnamese, but in Mandarin, it means 'very'; 'extremely'. thương (傷) has the meaning 'to like, to love', while also sharing the common meaning of 'to (be) injured, wounded' with Mandarin. thư (書) refers to a letter, while in Mandarin, it means book. (Vietnamese uses sách (冊) instead) There also a significant amount of Sino-Vietnamese compounds that are used, but the terms differ in different Sinosphere languages. Such as: +EnglishVietnameseMandarinCantoneseJapaneseKoreanuniversity studentsinh viên 生員大學生/大学生 dàxuéshēng大學生/大学生 daaihhohksāang大学生 daigakusei대학생 (大學生) daehaksaengprofessorgiáo sư 教師教授 jiàoshòu教授 gaausauh教授 kyōju교수 (敎授) gyosubachelor (academic degree)cử nhân 舉人學士/学士 xuéshì學士/学士 hohksih学士 gakushi학사 (學士) haksadoctorate (academic degree)tiến sĩ 進士博士 bóshì博士 boksih博士 hakushi박사 (博士) baksalibrarythư viện 書院圖書館/图书馆 túshūguǎn圖書館/图书馆 tòuhsyūgún図書館 toshokan도서관 (圖書館) doseogwanofficevăn phòng 文房事務所/事务所 shìwùsuǒ事務所/事务所 sihmouhsó事務所 jimusho사무소 (事務所) samusomapbản đồ 版圖地圖/地图 dìtú地圖/地图 deihtòuh地図 chizu지도 (地圖) jidoclockđồng hồ 銅壺鐘/钟 zhōng, 時計/时计 (literary) shíjì鍾/钟 jūng時計 tokei시계 (時計) sigyehotel; innkhách sạn 客棧酒店 jiǔdiàn, 旅館/旅馆 lǚguǎn酒店 jáudim, 旅館/旅馆 léuihgúnホテル hoteru, 旅館 (traditional inn) ryokan여관 (旅館) yeogwandemonstrationbiểu tình 表情示威 shìwēi示威 sihwāi示威 jii시위 (示威) siwiautism tự kỷ 自己自閉症/自闭症 zìbìzhèng自閉症/自闭症 jihbaijing自閉症 jiheishō자폐증 (自閉症) japyejeung

Self-coined Sino-Vietnamese compounds Some Sino-Vietnamese compounds are entirely invented by the Vietnamese and are not used in any Chinese languages, such as linh mục 'priest' from 'soul' and 'shepherd', or giả kim thuật ( 'art of artificial metal'), which has been applied popularly to refer to 'alchemy'. Another example is linh cẩu (, 'alert dog') meaning 'hyena'. Others are no longer used in modern Chinese languages or have other meanings.