Japanese is a language spoken by over 130 million people in Japan and in Japanese emigrant communities. It is a member of the Japonic (or Japanese-Ryukyuan) language family. There are a number of proposed relationships with other languages, but none have gained general acceptance. Japanese is classified as an Altaic language by many linguists, even more linguists see a connection with Korean. It is an agglutinative language and is distinguished by a complex system of honorifics reflecting the hierarchical nature of Japanese society, with verb forms and particular vocabulary to indicate the relative status of the speaker, the listener, and persons mentioned in conversation. The language has a relatively small sound inventory, and a lexically significant pitch-accent system. Japanese is a mora-timed language.

The Japanese language is written with a combination of three scripts: modified Chinese characters called kanji , and two syllabic scripts made up of modified Chinese characters, hiragana and katakana (カタカナ or 片仮名). The Latin alphabet, rōmaji , is also often used in modern Japanese, especially for company names and logos, advertising, and when entering Japanese text into a computer. Arabic numerals are generally used for numbers, but traditional Sino-Japanese numerals are also commonplace

Japanese vocabulary has been heavily influenced by loanwords from other languages. A vast number of words were borrowed from Chinese, or created from Chinese models, over a period of at least 1,500 years. Since the late 19th century, Japanese has borrowed a considerable number of words from Indo-European languages, primarily English. Because of the special trade relationship between Japan and first Portugal in the 16th century, and then mainly the Netherlands in the 17th century, Portuguese and Dutch have also been influential.

Although Japanese is spoken almost exclusively in Japan, it has been and sometimes still is spoken elsewhere. When Japan occupied Korea, Taiwan, parts of China, the Philippines, and various Pacific islands before and during World War II, locals in those countries were forced to learn Japanese in empire-building programs. As a result, many elderly people in these countries can speak Japanese in addition to the local language. Japanese emigrant communities sometimes employ Japanese as their primary language. Approximately 5% of Hawaii residents speak Japanese, with Japanese ancestry the largest single ancestry in the state. Japanese emigrants can also be found in Brazil, Peru, Argentina, Australia , the United States (notably California, where 1.2% of the population has Japanese ancestry, , and the Philippines . However, their descendants, known as nikkei rarely speak Japanese fluently after the second generation.

Japanese is the de facto official language of Japan. There is a form of the language considered standard: hyōjungo , meaning "standard Japanese", or kyōtsūgo , "common language". The meanings of the two terms are almost the same. Hyōjungo or kyōtsūgo is a conception that forms the counterpart of dialect. This normative language was born after the Meiji Restoration from the language spoken in the higher-class areas of Tokyo for communicating necessity. Hyōjungo is taught in schools and used on television and in official communications, and is the version of Japanese discussed in this article.

Formerly, standard Japanese in writing was different from colloquial language . The two systems have different rules of grammar and some variance in vocabulary. Bungo was the main method of writing Japanese until about 1900; since then kōgo gradually extended its influence and the two methods were both used in writing until the 1940s. Bungo still has some relevance for historians, literary scholars, and lawyers. Kōgo is the predominant method of both speaking and writing Japanese today, although bungo grammar and vocabulary are occasionally used in modern Japanese for effect. Literacy was introduced to Japan in the form of the Chinese writing system, by way of Baekje before the 5th century.Using this language, the Japanese king Yūryaku presented a petition to a Chinese emperor Liu Song in AD 478. After the ruin of Baekje, Japan invited scholars from China to learn more of the Chinese writing system. Japanese kings gave an official rank to Chinese scholars and spread the use of Chinese characters from the 7th century to the 8th century.

At first, the Japanese wrote in Classical Chinese, with Japanese names represented by characters used for their meanings and not their sounds. Later, during the seventh century AD, the Chinese-sounding phoneme principle was used to write pure Japanese poetry and prose, but some Japanese words were still written with characters for their meaning and not the original Chinese sound. This is when the history of Japanese as a written language begins in its own right. By this time, the Japanese language was already distinct from the Ryukyuan languages.The Korean settlers and their descendants used Kudara-on or Baekje pronunciation.

An example of this mixed style is the Kojiki, which was written in AD 712. They then started to use Chinese characters to write Japanese in a style known as man'yōgana, a syllabic script which used Chinese characters for their sounds in order to transcribe the words of Japanese speech syllable by syllable. Over time, a writing system evolved. Chinese characters (kanji) were used to write either words borrowed from Chinese, or Japanese words with the same or similar meanings. Chinese characters were also used to write grammatical elements, were simplified, and eventually became two syllabic scripts: hiragana and katakana.

Modern Japanese is written in a mixture of three main systems: kanji, characters of Chinese origin used to represent both Chinese loanwords into Japanese and a number of native Japanese morphemes; and two syllabaries: hiragana and katakana. The Latin alphabet is also sometimes used. Arabic numerals are much more common than the kanji when used in counting, but kanji numerals are still used in compounds, such as 統一 tōitsu ("unification").

Hiragana are used for words without kanji representation, for words no longer written in kanji, and also following kanji to show conjugational endings. Because of the way verbs (and adjectives) in Japanese are conjugated, kanji alone cannot fully convey Japanese tense and mood, as kanji cannot be subject to variation when written without losing its meaning. For this reason, hiragana are suffixed to the ends of kanji to show verb and adjective conjugations. Hiragana used in this way are called okurigana. Hiragana are also written in a superscript called furigana above or beside a kanji to show the proper reading. This is done to facilitate learning, as well as to clarify particularly old or obscure readings.

Historically, attempts to limit the number of kanji in use commenced in the mid-19th century, but did not become a matter of government intervention until after Japan's defeat in the Second World War. During the period of post-war occupation (and influenced by the views of some U.S. officials), various schemes including the complete abolition of kanji and exclusive use of rōmaji were considered. The jōyō kanji scheme arose as a compromise solution.

Japanese students begin to learn kanji from their first year at elementary school. A guideline created by the Japanese Ministry of Education, the list of kyōiku kanji , specifies the 1,006 simple characters a child is to learn by the end of sixth grade. Children continue to study another 939 characters in junior high school, covering in total 1,945 jōyō kanji. The official list of jōyō kanji was revised several times, but the total number of officially sanctioned characters remained largely unchanged.

As for kanji for personal names, the circumstances are somewhat complicated. Jōyō kanji and jinmeiyō kanji are approved for registering personal names. Names containing unapproved characters are denied registration. However, as with the list of jōyō kanji, criteria for inclusion were often arbitrary and led to many common and popular characters being disapproved for use. Under popular pressure and following a court decision holding the exclusion of common characters unlawful, the list of jinmeiyō kanji was substantially extended from 92 in 1951 to 983 in 2004. Furthermore, families whose names are not on these lists were permitted to continue using the older forms. Many writers rely on newspaper circulation to publish their work with officially sanctioned characters. This distribution method is more efficient than traditional pen and paper publications.
Study by non-native speakers

Many major universities throughout the world provide Japanese language courses, and a number of secondary and even primary schools worldwide offer courses in the language. International interest in the Japanese language dates from the 1800s but has become more prevalent following Japan's economic bubble of the 1980s and the global popularity of Japanese pop culture since the 1990s. About 2.3 million people studied the language worldwide in 2003: 900,000 South Koreans, 389,000 Chinese, 381,000 Australians, and 140,000 Americans study Japanese in lower and higher educational institutions.

In Japan, more than 90,000 foreign students study at Japanese universities and Japanese language schools, including 77,000 Chinese and 15,000 South Koreans in 2003. In addition, local governments and some NPO groups provide free Japanese language classes for foreign residents, including Japanese Brazilians and foreigners married to Japanese nationals. In the United Kingdom, studies are supported by the British Association for Japanese Studies. In Ireland, Japanese is offered as a language in the Leaving Certificate in some schools.

The Japanese government provides standardised tests to measure spoken and written comprehension of Japanese for second language learners; the most prominent is the Japanese Language Proficiency Test (JLPT), which features 4 levels of exams, ranging from elementary (4) to advanced (1). The Japanese External Trade Organization JETRO organizes the Business Japanese Proficiency Test which tests the learner's ability to understand Japanese in a business setting.

When learning Japanese in a college setting, students are usually first taught how to pronounce romaji. From that point, they are taught the two main syllabaries, with kanji usually being introduced in the second semester. Focus is usually first on polite (distal) speech, as students who might interact with native speakers would be expected to use. Casual speech and formal speech usually follow polite speech, as well as the usage of honorific.