Sino-Japanese

The expression Sino-Japanese refers to the Chinese language as traditionally pronounced by speakers of Japanese. Chinese vocabulary has exerted an enormous effect on Japanese, because at the time of their first contact, Japanese had no written form. The earliest written language to be used in Japan was in fact literary Chinese, which was called kanbun in this context. Use of kanbun essentially required every literate Japanese to be competent in Chinese. The spoken form of kanbun, that is, the approximation by the Japanese of the then-current Chinese pronunciation, was Sino-Japanese. Later, the modern system of kanji and kana was developed, which enabled Japanese per se to be written using Chinese-based characters. However, many of the Sino-Japanese words were taken into the general vocabulary as loanwords; these are the onyomi readings of kanji.

Sino-Japanese is very important for comparative linguists as it provides a large amount of evidence to allow the reconstruction of Middle Chinese.

At first glance, Sino-Japanese words will often not appear to be of Chinese origin at all. However, the observed differences are caused by the nature and history of the two languages involved. What follows is a rough guide for understanding equivalencies between modern Mandarin Chinese words and modern Sino-Japanese onyomi readings:

1. A major sound-shift occurred in Mandarin during the last 400 years in which the "g" or "k" sound, when immediately preceding an "i", "y" or "ü" sound, became "j" or "q" (hence Peking (北京) to Běijīng or Chungking (重慶) to Chóngqìng). This shift is not reflected in Sino-Japanese. Thus Chinese qì (氣, breath) corresponds to Japanese ki.
2. The Japanese language does not have an "-ng" sound, although it is very common in Chinese. This sound is usually omitted completely, and the vowel of the affected syllable is often changed to an "o". Thus Chinese Dōngjīng (eastern capital) corresponds to Japanese Tōkyō (東京).
3. In general, a language's vowel sounds are more malleable than its consonant sounds, so we will learn more by comparing the latter than the former. The vowels of Chinese will sometimes change unpredictably en route to Sino-Japanese. However, we can note that Chinese "ao" often becomes Japanese "o" and Chinese empty rime \\ʅ\\, represented with an "i", often becomes a standard "i" \\i\\ in Japanese.
4. The distinction between voiced and unvoiced consonants ("d" vs. "t" or "b" vs. "p") has historically not been made clearly in Chinese. Thus a voiced consonsant in Chinese will often correspond to an unvoiced one in Sino-Japanese, and vice versa (i.e. b=p, ch=j, d=t, g=k).
5. In modern Mandarin, syllables can only end in a vowel or in one of a small number of consonant sounds: "n", "ng", or occasionally "r". Premodern Chinese, however, allowed several other final consonants, such k, g, t, or d, which are preserved in Sino-Japanese. However, because these consonants cannot appear at the end of syllables in Japanese either, they are usually followed in Sino-Japanese by an additional "i" or "u" vowel sound (as a result, a one-syllable word in Chinese can become two syllables in Japanese). For example, Chinese tiě (铁, iron) corresponds to Japanese tetsu (鉄).
6. The consonant "f" in Chinese often becomes "b" in Japanese. Thus, Chinese Fó (佛, Buddha) corresponds to Japanese Butsu (仏); both derive from the archaic Chinese Bud. Note that this pattern appears in Latin and English as well: Latin frater corresponds to English brother.
7. The modern Chinese consonant "r" usually becomes "ny" or "ni" in Japanese. Thus Chinese Rìběn (日本, Japan) corresponds to Japanese Nippon.
8. The Chinese "hu" consonant sound (as in "huá" or "huī") does not exist in Japanese and is usually omitted, whereas the Chinese "l" sound becomes "r" in Japanese. Thus, Chinese Huángbò (黄檗) corresponds to Japanese Ōbaku, and Rúlái (如来) to Nyorai.
9. Chinese "h" will often become "k" in Japanese, "z" will often become "j", and w will often become b or m. Thus, Chinese \hànzì (漢字) corresponds to Japanese kanji, and hànwén (漢文, Chinese written language) to kanbun.