Japanese grammar


is an agglutinative, synthetic, 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. Its phrases are exclusively head-final and compound sentences are exclusively left-branching. 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 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.
In language typology, it has many features different from most European languages.

Distinctive aspects of modern Japanese sentence structure

Word order: head-final and left-branching

The modern theory of constituent order, usually attributed to Joseph Harold Greenberg, identifies several kinds of phrases. Each one has a head and possibly a modifier. The head of a phrase either precedes its modifier or follows it. Some of these phrase types, with the head marked in boldface, are:
  • genitive phrase, i.e., noun modified by another noun ;
  • noun governed by an adposition ;
  • comparison.
  • noun modified by an adjective.
Some languages are inconsistent in constituent order, having a mixture of head-initial phrase types and head-final phrase types. Looking at the preceding list, English for example is mostly head-initial, but nouns follow the adjectives which modify them. Moreover, genitive phrases can be either head-initial or head-final in English. By contrast, the Japanese language is consistently head-final:
  • genitive phrase:
  • noun governed by an adposition:
  • comparison:
  • noun modified by an adjective:
Head-finality in Japanese sentence structure carries over to the building of sentences using other sentences. In sentences that have other sentences as constituents, the subordinated sentences, always precede what they refer to, since they are modifiers and what they modify has the syntactic status of phrasal head. Translating the phrase "the man who was walking down the street" into Japanese word order would be "street down walking was man".
Head-finality prevails also when sentences are coordinated instead of subordinated. In the world's languages, it is common to avoid repetition between coordinated clauses by optionally deleting a constituent common to the two parts, as in "Bob bought his mother some flowers and his father a tie", where the second bought is omitted. In Japanese, such "gapping" must proceed in the reverse order: "Bob mother for some flowers and father for tie bought". The reason for this is that in Japanese, sentences always end in a verb —the only exceptions being a few sentence-ending particles such as,, and. The particle turns a statement into a question, while the others express the speaker's attitude towards the statement.

Word class system

Japanese has five major lexical word classes:
  • nouns
  • verbal nouns
  • Adjectival noun
  • verbs
  • Japanese adjectives
More broadly, there are two classes: uninflectable and inflectable. To be precise, a verbal noun is simply a noun to which the light verb can be appended, while an adjectival noun is like a noun but uses instead of when acting attributively. Adjectives inflect identically to the negative form of verbs, which end in. Compare → and →.
Some scholars, such as Eleanor Harz Jorden, refer to adjectives instead as adjectivals, since they are grammatically distinct from adjectives: they can predicate a sentence. That is, is glossed as "hot" when modifying a noun phrase, as in, but as "is hot" when predicating, as in.

Open and closed classes

The two inflected classes, verb and adjective, are historically considered closed classes, meaning they do not readily gain new members—but see the following paragraphs. Instead, new and borrowed verbs and adjectives are typically conjugated periphrastically as verbal noun + and adjectival noun +. This differs from Indo-European languages, where verbs and adjectives are open classes, though analogous "do" constructions exist, including English "do a favor", "do the twist" or French "faire un footing", and periphrastic constructions are common for other senses, like "try climbing" or "try parkour". Other languages where verbs are a closed class include Basque: very few Basque verbs have synthetic conjugation, all the others are only formed periphrastically. Conversely, pronouns are closed classes in Western languages but open classes in Japanese and some other East Asian languages.
In a few cases historically, and much more commonly recently, new verbs are created by appending the suffix to a noun or using it to replace the end of a word. This is most often, but not exclusively, done with borrowed words, and results in a word written in a mixture of katakana and hiragana, which is otherwise very rare. This is typically casual, with the most well-established example being , from, with other common examples including, from memo, and from. In cases where the borrowed word already ends with or even contains a or, this may be rebracketed as a verb ending and changed to a, as in, from ;, from ; and, from. New verbs coined in this fashion are uniformly group 1 verbs and, at least in the Tokyo accent, consistently are stressed immediately before the final る.
New adjectives are extremely rare; one example is, from adjectival noun, and a more casual recent example is, by contraction of. By contrast, in Old Japanese adjectives were open, as reflected in words like, from the adjective, and, from the noun . Japanese adjectives are unusual in being closed class but quite numerous – about 700 adjectives – while most languages with closed class adjectives have very few. Some believe this is due to a grammatical change of inflection from an aspect system to a tense system, with adjectives predating the change.
The conjugation of -adjectives has similarities to the conjugation of verbs, unlike Western languages where inflection of adjectives, where it exists, is more likely to have similarities to the declension of nouns. Verbs and adjectives being closely related is unusual from the perspective of English, but is a common case across languages generally, and one may consider Japanese adjectives as a kind of stative verb.
Japanese vocabulary has a large layer of Chinese loanwords, nearly all of which go back more than one thousand years, yet virtually none of them are verbs or "-adjectives" – they are all nouns, of which some are verbal nouns and some are adjectival nouns. In addition to the basic verbal noun + form, verbal nouns with a single-character root often experienced sound changes, such as → →, as in, and some cases where the stem underwent sound change, as in, from.
Verbal nouns are uncontroversially nouns, having only minor syntactic differences to distinguish them from pure nouns like 'mountain'. There are some minor distinctions within verbal nouns, most notably that some primarily conjugate as , more like nouns, while others primarily conjugate as, and others are common either way. For example, is much more common than, while is much more common than. Adjectival nouns have more syntactic differences versus pure nouns, and traditionally were considered more separate, but they, too, are ultimately a subcategory of nouns.
There are a few minor word classes that are related to adjectival nouns, namely the adjectives and adjectives. Of these, adjectives are fossils of earlier forms of adjectives, and are typically classed separately, while adjectives are a parallel class, but are typically classed with adjectives.

Different classifications

The first structured description of the Japanese parts of speech was in, an 1831 grammar by Tsurumine Shigenobu. It was based on earlier Dutch grammars such as Shizuki Tadao's and. The words hinshi and shihin also came about from these early late-Edo and early-Meiji grammars. Since then, there have been multiple conflicting classifications of the parts of speech of Japanese.
The term assumed different meanings, such as a verb form that precedes a noun, or as a proposed alternative to, because Japanese "adjectives" are verb-like in nature, unlike European adjectives. As shown in the table, Matsushita Daizaburō used keiyōshi explicitly for the Eurocentric idea of adjectives as words that precede nouns, while reserving keiyō dōshi for Japanese "adjectives" as verb-like words. Ochiai Naobumi defined keiyō dōshi not as a grammatical category, but as a semantic one with meanings similar to those of stative verbs. It was not until Haga Yaichi's usage in 1905 that keiyō dōshi came to be refer to adjectival words whose ended with or .
The of today has followed Iwabuchi Etsutarō's model outlined in his 1943 grammar,, compiled for the Ministry of Education, Science, Sports and Culture. It recognizes 10 parts of speech as shown in the table.
Among historical classifications, the grammarian Matsushita Daizaburō notably compared his own terminology to the terminologies translated from and modeled after European ones at the time. In particular, he rejected the equation of what were dubbed in Japanese to the concept of "adjectives" in European grammars, although he revised his systems over the years, which ended up conforming to the popular usage of the term keiyōshi. According to Matsushita :
The distinction between Japanese so-called "adjectives" and European true adjectives reflect in how differently they inflect. European adjectives are a type of nouns, that is, words that decline and express case, gender and number, and that include substantive nouns, adjective nouns, numeral nouns and pronouns. Japanese "adjectives", on the other hand, do not decline, but conjugate and express tense, mood, aspect, evidentiality, etc., and thus are more similar to European verbs.