Adjectival noun (Japanese)

The terminology used to refer to this word-class is inconsistent. The Japanese name is 形容動詞 keiyō dōshi, which literally means "adjectival verb". This is not necessarily at odds with the English term adjectival noun, since in traditional Japanese grammar, keiyō dōshi includes the copula, while the adjectival noun in the analysis described here does not include the copula. For example, in the traditional grammar, kirei da is a keiyō dōshi and kirei is its stem; in the analysis here, kirei is an adjectival noun and kirei da is its combination with the copula. Considering the copula is a kind of verb and kirei is a kind of noun syntactically, both terminologies make sense.

Grammatically, these words are similar to nouns, or more technically, nominals, which function attributively (like adjectives). The main differences between these and regular nouns are that nouns take a 〜の -no suffix when acting attributively, while these words take a 〜な -na suffix when acting attributively; most of these words cannot be used as the agent or patient (i.e. subject) of a sentence; and most of these words cannot be modified by relative clauses. Aside from these differences, Japanese adjectival nouns and regular nouns behave the same way in terms of grammar. They are variously referred to as "adjectival verbs" (literal translation), "adjectival nouns" (nouns that function adjectivally), "na adjectives" (function as adjectives, take na), and "na nominals" (nominals that take na). For example, Eleanor Harz Jorden refers to them as "na-nominals" in her textbook Japanese: The Spoken Language.

In fact, by some analyses, nouns and na-nominals are fundamentally grammatically the same, where 〜の vs. 〜な when used attributively is simply a conventional stylistic complementary distribution, with 〜の／〜な being allomorphs. This view is reinforced by the fact that some words, such as 特別 tokubetsu "special", can take either a 〜の or a 〜な, depending on the phrase.[1] Ultimately, 〜な is an abbreviation of 〜にある, used to use a noun attributively (compare modern 〜である, which is a more recent form), while 〜の is the genitive case;[1] see etymology, below.

In traditional Japanese grammar, adjectival nouns are considered "inflectional", katsuyō, like verbs and i-adjectives, rather than non-inflectional hikatsuyōgo (非活用語) or mukatsuyōgo (無活用語), like nouns.

This is a point of disagreement in current Japanese grammar, and authors such as Uehara (1998)[2] argue that instead, adjectival nouns should be classed with nouns as non-inflectional.

The claim that na-adjectives are inflectional rests on the claim that the syllable da 'is', usually regarded as a "copula verb", is really a suffix – an inflection. Thus, hon 'book', generates a one-word sentence, honda 'it is a book', not a two-word sentence, hon da. However, numerous constructions seem to be incompatible with the suffixal copula claim.

(1) Reduplication for emphasis

Hora! Hon, hon! 'See, it is a book!'

Hora! Kirei, kirei! 'See, it is pretty!'

Hora! Furui, furui! 'See, it is old!' (the adjectival inflection -i cannot be left off)

Hora! Iku, iku! 'See, it does go!' (the verbal inflection -u cannot be left off)

(2) Questions. In Japanese, questions are formed by adding the particle ka (or in colloquial speech, just by changing the intonation of the sentence).

Hon/kirei ka? 'Is it a book? ; Is it pretty?'

Furu-i/Ik-u ka? 'Is it old? ; Does it go?' (the inflections cannot be left off)

(3) Several auxiliary verbs, e.g., mitai, 'looks like it's'

Hon mitai da; Kirei mitai da 'It seems to be a book; It seems to be pretty'

Furu-i mitai da; Ik-u mitai da 'It seems to be old; It seems to go'

On the basis of such constructions, Uehara (1998) finds that the copula is indeed an independent word, and that regarding the parameters on which i-adjectives share the syntactic pattern of verbs, the nominal adjectives pattern with pure nouns instead.

In Late Old Japanese (below), a separate kind of tari adjectival nouns developed alongside the existing nari ones (nari, tari were the conclusive forms, while naru, taru were the attributive forms). The nari ones developed into the adjectival nouns (naru contracted to na, while nari was replaced by da (the copula)) that are the subject of this article, while the tari ones mostly died out over the course of Late Middle Japanese, being mostly gone by Early Modern Japanese, surviving as fossils in a few words which are generally considered somewhat stiff or archaic. These are generally referred to as ト・タル形容動詞 (to, taru keiyōdōshi) or タルト型活用 (taruto-kata katsuyō – “taru, to form conjugation”), and can also function adverbially with 〜と -to, instead of the 〜に -ni which is mostly used with な nominals. See taru adjectives for further discussion in English, and 形容動詞#タルト型活用 for Japanese.

There is one type of adjectival noun in modern usage, with inflections as follows.

• The modern inflections are based on two primitive forms: d- and n-. The n- forms are historically older while the d- forms are newer and have replaced some of the older n- forms.
• Irrealis -daro is found with particle -u, resulting in -darou (-darō). Historically it was -dara. /au/ regularly changed into [ō].
• Adverbial -daQ is often found with past particle -ta, resulting in "daQta" -> "datta".
• Adverbial -de is found before "aru" and "nai", as well as being used in to terminate one clause before beginning another (中止法).
• Adverbial -ni is used in adverbial constructions.
• Modern Japanese no longer inflects for imperative.

Japanese adjectival nouns differ in etymological origin from adjectival verbs. Whereas adjectival verbs are almost entirely native in origin, the class of adjectival nouns comprises mostly foreign loanwords and a small subset of polymorphemic native words.[3][4] All words listed in this section take the attributive -na and predicative -da copula.

The internal properties of Japanese adjectival nouns can be analysed either through a lexical features approach or through a Distributed Morphology approach.

Morphological tree structure

The internal morphological structure of Japanese adjectival phrases can be represented by the following trees:

Adjectival Noun	Adjectival Verb	Noun

Within the tree structures, the word root combines with the functional category n0 to become a noun, then combine with the functional head a0 to form an adjective. Both nouns and adjectives contain the root-n0 combination, and it is the presence of a0 that results in the appearance of the attributive copula -na.[6]

• Japanese adjectives
• Japanese grammar
• Japanese verb conjugation