Chapter 5. Nouns and noun adjectives

Table of Contents

With all this verbal talk going on you would almost forget that Japanese also has nominals - nouns and noun adjectives. Since these words are not verbal, they have to rely on the copula です/だ for inflections. Before we look at these forms though, we need to look at the differences between pure nouns and noun adjectives in Japanese, as there is a subtle difference.

1. Genitive vs. attributive

As mentioned in the outline, nouns and noun adjectives differ in the way they "chain up" so to speak. While nouns can only be placed in a genitive relation, expressing things like "Bob's mother's teacup", noun adjectives work like adjectives rather than nouns when chained. However, in dictionary form, you cannot tell what is a noun and what is a noun adjective; this difference is only visible when we start chaining them:

Here we have chained two nouns, 彼 (he) and 車 (car), to form the genitive chain "his car".

Again we chain only nouns, to form the genitive chain "his sister's car". Now, if we use noun adjectives, we see an adjectival な instead of a genitive の:

The words 危険 and こと on themselves are nouns, but when we try to create a noun chain with 危険, it acts adjectival, not nominal. That is, instead of a の to indicate a genitive relation, we see a な that indicates an adjectival relation.

To make matters more confusing, as mentioned in the section on だ, the plain copula can become な when followed by の, such as for instance in the grammatical pattern [... の事...] or [...の/んです]. This means that both nouns and noun adjectives in sentences like "本だ" ("it is a book", using a noun + だ) or "きれいだ" ("it is pretty", using noun adjective + だ), get な instead, again offering no way to tell if something is a noun or noun adjective other than to simply remember which word was of which word class.

2. Inflections using です

Conjugating these words is essentially infecting です, and adding this to the noun or noun adjective:

For more conjugations for nominals, which are just the inflections of だ/です, see the conjugation scheme in the following section.

3. Noun conditional

There is one 'inflection' that needs to be mentioned separately because while it technically relies on だ, this is not apparent from its form, namely the noun conditional. In English this is the conditional in statements like "should it be a [noun], then ..." or "if it's a [noun], then ...". In Japanese these statements are made with the 已然形 of だ, なら:

One can either use なら, or add the hypothetical particle ば as is normally done for verbs. The choice of using なら or ならば is reasonably arbitrary, and the rule "the longer it is, the more formal it sounds" applies here:

These two sentences mean the exact same thing, but the second sentence sounds slightly more formal because of the use of ならば rather than なら. Again, one should remember that while using "if" in a translation typically suits the translated sentence, the real connotation of なら(ば) is "Should it be ...", since this is an 已然形 + ば construction for the plain copulate だ (another bit of mystery for だ, why is its 已然形 なら? Just how much can this helper verb change?)