I and Na Adjectives: What the textbooks don’t tell you

i-and-na-adjectives
Enpitsu ga akai. The pencil is red and it writes its own “is”

Like most of Japanese grammar, i and na-adjectives are simple, logical and beautiful. As far as I have seen (and I don’t claim to have seen everything) introductions to grammar do not explain them very clearly.

In a way I can see why. Their aim is to “cut to the chase” and tell you how to use them in practice. The trouble is, to my way of thinking, that this cutting-to-the-chase leaves the impression of a bundle of random quirky “facts” that you have to learn, rather than a complete, clear and beautiful system.

This in turn makes it harder to learn to use them correctly by instinct.

So let me tell you what I think everyone should know from day one of using i and na adjectives (but please use this in conjunction with a conventional explanation of their actual use if you aren’t familiar with it).

Video version of this article:

1. Na adjectives are essentially nouns. They work like nouns. That is why they need “na” (I’ll explain that bit in a moment).

2. I adjectives are close cousins of verbs. They conjugate like verbs. Na adjectives don’t because nouns don’t conjugate.

3. The “is” function is built into i adjectives. Kirei (na adjective) means “pretty” (or “prettiness”). But utsukushii (i adjective) does not mean “beautiful”, it means “is beautiful”. I put this in red because it is so important.

Now something happens from lesson one that tends to throw this important point into confusion. We learn:

Hana ga kirei desu (“the flower is pretty”: na-adj)

Hana ga akai desu (“the flower is red”: i-adj)

So don’t the two kinds of adjective work identically? Don’t they both require desu?

No, they don’t. The desu on kirei is grammatically necessary. The desu on akai is only used to make the sentence desu/masu polite level. It serves no grammatical function.

That is why, in plain form, we say:

Hana ga kirei da

Hana ga akai

Hana ga akai is the grammatically complete and proper way to say it. Hana ga kirei needs da.

And now that you know this, you are ready for the next important fact.

4. Na is a form of da. “So that is why na adjectives need na! Why didn’t anyone mention that?” You exclaim. So did I.

Connecting two i or na-adjectives

So, when you connect two verb-like i-adjectives, what do you do? You do just what you do when you connect verbs to something. You put them into te-form.

chiisakute kawaii = “is small and cute” (note that converting the final い i to く ku is the “glue” that holds conjugations onto i-adjectives).

And what do you do with na adjectives? Exactly the same thing.

But you can’t conjugate nouns or noun-like adjectives. No. And that is why na adjectives need na/da/desu. And that does conjugate to te-form.

The te-form of da/desu is de. So:

Kirei de yuumei da “is pretty and famous”.

I think I spent about a month wondering why the de particle was used in such an unpredictable way here. Of course, this de is not the de particle. It is the te-form of that same na/da/desu that always has to appear after a na-adjective.

As you see, the process is identical. chiisai means “is small”. To make kirei mean “is pretty” (rather than just “pretty”, or really something closer to “prettiness”) you have to add na/da. Both are then put into te-form:

chiisai chiisakute

kirei na kirei de.

Naturally you can join an i-adjective to a na-adjective, or a naadjective to an i-adjective, just so long as you use the appropriate te-form as the connector for the first one.

These are the things I wish I had known right from the start, so I am giving them to you. I hope they make this aspect of Japanese feel clearer, easier and more kirei for you just as they did for me.

You may also want to watch this video, which goes into the broader question of “adjectival” use in Japanese including the way verbs and regular nouns also act in an adjectival capacity – forming one of the fundamental mechanisms of Japanese grammar:

One last point that can cause a little confusion. You will sometimes see the words ookii (big) and chiisai (small) used with the final i replaced by na. These are the only two adjectives that are commonly used as both i and na adjectives (though occasionally others can be too). The effect of the na-form is to make them feel a little more childlike and story-bookish. As in the children’s song Ookina kuri no ki no shita de “Under the big chestnut tree”.

This article comes from Unlocking Japanese, if you would like to learn how not only adjectives but most of Japanese is far easier clearer and more logical than the textbooks ever tell you, get your copy now!

13 thoughts on “I and Na Adjectives: What the textbooks don’t tell you

  1. Thank you, thank you, thank you! I have been wondering how this worked for weeks, and I was sure that there was a simple explanation, but I didn’t know what to look for. This makes total sense and fits perfectly with my observations.

  2. Thank you for your kind comments. I do understand why textbooks and teachers don’t want to get over-explanatory and just tell people “what to do”, but understanding how it all fits together makes a huge difference, I think.

    It also stops one making a lot of mistakes because one can see why things are what they are rather than just trying to apply a set of apparently arbitrary rules blindly.

  3. Then there’s that moment when you realize the adjective conjugations are just forms of “aru” stuck on the adverbial form, and you feel like you can control space and time with the power of your mind…

  4. i am still confused because i still see desu after the i adjective as well, but can you answer this for me because this may clear everything up for me. the i adjective are like big small fast ect.. where the na is all emotions that someone would have like if someone thinks its pretty or necessary or cute or attractive.. sorry for my bad wording hopefully you know what i am saying. if i am wrong please let me know.

    1. As I said in the video, this is because with real adjectives (i-adjectives) です is a decoration or formality-marker. it serves no grammatical function. It is just tacked on to make the sentence formal. I agree it is confusing and this is one of the reasons that I think it is wrong to teach てす・ます Japanese before teaching the plain language. It always confuses people.

  5. like the i-adj states a fact where na-adj is opinion based. thats what im seeing when i see a list, not saying i am right i am just curious

    1. There is no real meaning distinction between adjectives (=”i adjectives”) and so-called “na adjectives”. The difference is structural. I-adjectives are actually adjectives and “na-adjectives” are nouns that work as adjectives by adding だ or な. Historically the reason is that “na-adjectives” are mostly words of Chinese origin and all foreign words enter Japanese as nouns. There are well-established strategies for using a noun as an adjective or a verb. So that is why “na-adjectives” exist.

  6. Thank you sooo much you just saved me from much more confusion with this amazing article :”) <3

  7. Do you have an article on conjugating adjectives?
    I heard my teacher say ” suki ta kat_ta” the other day, and I’ve always used suki deshita for the past. Can you help me understand the “ta ka_ta” part? I get that’s how you conjugate “i” adjectives, but isn’t suki a na adjective?

    1. Suki is a noun and you can never “conjugate” nouns. So-called “na adjectives” are all nouns. So I think you must have misheard. たかった is not how you “conjugate” real (i) adjectives either.

      The past of adjectives is simply かった. たかった usually means that the helper adjective たい (expressing wanting to do) has been added to a verb and put into the past tense.

      The teacher may have said すきだった which would mean “liked”. The copula だ is in the past tense. This is basic Japanese rather than the complex です・ます version which should never be taught until people know the basic language.

  8. I’m still so confused. Everyone seems to get it. The na adjective kirai is one that means to dislike how is that a noun? and ookii means large and is a i adjective but that isn’t a close to a verb.

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