Little is known of the language's prehistory, or when it first appeared in Japan. 3rd century Chinese documents recorded a few Japanese words, but substantial texts did not appear until the 8th century. During the Heian period (794–1185), Chinese had a considerable influence on the vocabulary and phonology of Old Japanese. Late Middle Japanese (1185–1600) saw changes in features that brought it closer to the modern language, as well 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 has 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, gender or article aspect. Verbs are conjugated, primarily 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.