No language is an island; as long as there is language contact, words get borrowed. This is especially true when one language possesses a dominant, influential culture in relation to the adjacent culture. This section traces the history of lexical borrowing. We will then say a few things that relate to lexical borrowing and what they might relate to Japanese society.
Chinese as the Main Source of Borrowing
Borrowing vocabulary began at the dawn of the historical period in Japan, when it began borrowing a large amount of vocabulary from China, a country which had an advanced civilization. Japanese borrowed all types of vocabulary to describe all domains of human activity, including social structure, government and politics, art and architecture, religion, law, food and food preparation, agriculture, math, etc. Of course, this is not to say that Japanese did not have its own vocabulary, but these new imports filled important gaps in the Japanese lexicon, gaps that became apparent when a huge infusion of knowledge made its way into Japan.
An example of borrowing that took place early is found in the numerical system. Anyone who has studied Japanese can attest that Japanese has two numerical series—one native (hi, fu, mi, yo, . . .) and other Chinese (ichi, ni, san, shi, . . .)—which coexist even today. The Chinese series was base-ten and capable of representing the notion of zero. It also allowed counting to sufficiently high numbers for all practical purposes, while the Japanese native numerals began at 1 and went only a few beyond 10 (14 was too amari yon 'ten with four left over')—not practical for mathematical tasks required for, for instance, collecting tax or keeping inventory, and practically impossible without a writing system. In addition to math, Chinese model was important for almost all spheres of activity, including city planning (e.g., the city of Kyoto and Nara were laid out using the Chinese civil engineering knowledge and city planning), building buildings (e.g., Hōryūji a temple in Nara built around A.D. 700), government and taxation structure, just to name the most obvious. It was not an overstatement to say that between 4th century and the end of the Nara period (710-784), China provided much of Japan's technology and advanced knowledge and, consequently, terminology in these areas. As we learn elsewhere, Chinese words (or any foreign words for that matter) borrowed by Japanese underwent change in sound so they would fit into the Japanese language structure and in meaning to suit relevant Japanese style of life.
Words that came into Japanese during this early period include daiji 大慈 'Buddha's compassionate love,' zizai 自在 'Goddess Siva' (Sanskrit Siva, Isvara), baramon 婆羅門 (from Sanskrit brahmana, 'highest Hindu caste'), rikizi 力士 'guardian god' (Chinese translation of Sanskrit Vajradhara), ruri 瑠璃 'lapis lazuli,' riyaku 利益 'acts of charity benefiting others,' cha 茶 'tea,' kwa 菓 'fruit' (Modern Japanese ka), kau 香 'insence' (Modern Japanese kō), kū 功 'achievement' (Modern Japanese kō), kuwaso 過所 'permission to pass' (Modern Japanese kasho), gowi 五位 'Rank Five' (Modern Japanese goi), suguroku 双六 'a type of board game,' puse 布施 '(monetary) offering' (Modern Japanese fuse; Chinese translation of Sanskrit dana), housi 法師 'Buddhist monk' (Modern Japanese hōsi). In addition to Chinese, Japanese borrowed from Korean and Ainu as well. Korean borrowing included kasa 笠 'hat,' kama 窯 'kiln,' and hata 機織 'weaving machine.' From Ainu, we have emisi 蝦夷 (Modern Japanese ezo 'Ainu, Hokkaidō') and kaniha 桜皮 'cherry tree bark.' It is widely believed that words having word initial voiced consonants, CyV sequences (such as cha 茶 'tea'), and word initial liquid /r/ were not native to the Japanese language and were brought in from Chinese. This serves as an early example for language's sound structure being permanently altered due to the influence of borrowed words. We will have more to say on this at the end of this essay.