Little is known of the language's prehistory, or when it first appeared in Japan. Chinese documents from the 3rd century recorded a few Japanese words, but substantial texts did not appear until the 8th century. During the Heian period (794–1185), Chinese had considerable influence on the vocabulary and phonology of Old Japanese. Late Middle Japanese (1185–1600) included changes in features that brought it closer to the modern language, and the first appearance of European loanwords. The standard dialect moved from the Kansai region to the Edo (modern Tokyo) region in the Early Modern Japanese period (early 17th century–mid-19th century). Following the end in 1853 of Japan's self-imposed isolation, the flow of loanwords from European languages increased significantly. English loanwords, in particular, have become frequent, and Japanese words from English roots have proliferated.
Japanese is an agglutinative, mora-timed language with simple phonotactics, a pure vowel system, phonemic vowel and consonant length, and a lexically significant pitch-accent. Word order is normally subject–object–verb with particles marking the grammatical function of words, and sentence structure is topic–comment. Sentence-final particles are used to add emotional or emphatic impact, or make questions. Nouns have no grammatical number or gender, and there are no articles. Verbs are conjugated, primarily for tense and voice, but not person. Japanese equivalents of adjectives are also conjugated. Japanese has a complex system of honorifics with verb forms and vocabulary to indicate the relative status of the speaker, the listener, and persons mentioned.
Japanese has no genetic relationship with Chinese, but it makes extensive use of Chinese characters, or kanji (漢字), in its writing system, and a large portion of its vocabulary is borrowed from Chinese. Along with kanji, the Japanese writing system primarily uses two syllabic (or moraic) scripts, hiragana (ひらがな or 平仮名) and katakana (カタカナ or 片仮名). Latin script is used in a limited fashion, such as for imported acronyms, and the numeral system uses mostly Arabic numerals alongside traditional Chinese numerals.
A common ancestor of Japanese and Ryukyuan languages or dialects is thought to have been brought to Japan by settlers coming from either continental Asia or nearby Pacific islands sometime in the early- to mid-2nd century BC (the Yayoi period), replacing the languages of the original Jōmon inhabitants, including the ancestor of the modern Ainu language. Very little is known about the Japanese of this period. Because writing like the "Kanji" which later devolved into the writing systems "Hiragana" and "Katakana" had yet to be introduced from China, there is no direct evidence, and anything that can be discerned about this period of Japanese must be based on the reconstructions of Old Japanese.
Old Japanese is the oldest attested stage of the Japanese language. Through the spread of Buddhism, the Chinese writing system was imported to Japan. The earliest texts found in Japan are written in Classical Chinese, but they may have been meant to be read as Japanese by the kanbun method. Some of these Chinese texts show the influences of Japanese grammar, such as the word order (for example, placing the verb after the object). In these hybrid texts, Chinese characters are also occasionally used phonetically to represent Japanese particles. The earliest text, the Kojiki, dates to the early 8th century, and was written entirely in Chinese characters. The end of Old Japanese coincides with the end of the Nara period in 794. Old Japanese uses the Man'yōgana system of writing, which uses kanji for their phonetic as well as semantic values. Based on the Man'yōgana system, Old Japanese can be reconstructed as having 88 distinct syllables. Texts written with Man'yōgana use two different kanji for each of the syllables now pronounced き ki, ひ hi, み mi, け ke, へ he, め me, こ ko, そ so, と to, の no, も mo, よ yo and ろ ro. (The Kojiki has 88, but all later texts have 87. The distinction between mo1 and mo2 apparently was lost immediately following its composition.) This set of syllables shrank to 67 in Early Middle Japanese, though some were added through Chinese influence.