Japanese adjectives, like English adjectives, are words that we use to describe . In a Japanese sentence, the adjective can either come before the noun it modifies or at the end of the sentence.
An adjective before a noun forms a
おいしい 寿司
oishii sushi
delicious sushi
An adjective at the end of a sentence is used like you might use “to be” + adjective in English:
この寿司はおいしい
kono sushi wa oishii
This sushi is delicious.
However, it’s not always quite so simple! Japanese adjectives sometimes take endings, and those endings follow two different grammatical patterns, depending on what kind of adjective you use. The two types of Japanese adjectives are i-adjectives and na-adjectives.
In this post, we’ll introduce you to the difference between i-adjectives and na-adjectives, chat about how to “conjugate” adjectives (and what it means to do so!), and give you some tips that will help you get started using adjectives in Japanese. Ready to take a look? Let’s dive in!
Japanese adjectives fall into two groups: i-adjectives and na-adjectives. The group an adjective belongs to will determine exactly how you should use it in a sentence, both before a noun and in “be” + adjective sentences.
In this section, we’ll introduce you to the differences between these two groups and discuss where they get their names.
In Japanese, i-adjectives (or i-type adjectives) are adjectives whose dictionary form can be placed directly in front of the noun they describe:
i-adjective
dictionary form
noun
木下先生は いい 車に乗っている。
Kinoshita sensei wa ii kuruma ni notte iru.
Professor Kinoshita rides a nice car.
おいしい カレーが食べたい。
Oishii karē ga tabetai.
I want to eat delicious curry.
All i-adjectives have a dictionary form that ends with い[i]. This is the source of their name. For example:
いい
ii
good, nice
赤い
akai
red
おいしい
oishii
tasty, delicious
おとなしい
otonashii
gentle, docile
Not all adjectives that end in い[i] are i-adjectives. Some na-adjectives can also take this ending.
So while the い[i] ending might suggest that it’s an i-adjective, you’ll ultimately need to memorize which adjectives are i-adjectives and which ones aren’t. This information should be listed in a dictionary, but there are also some tricks you can use which we’ll cover below.
Japanese na-adjectives are adjectives that can only come before a noun if they are followed by な[na], as in the structure below:
na-adjective
dictionary form
な
na
noun
カールさんは元気な人だなあ。
Kāru san wa genki na hito da nā.
What an energetic person Carl is!
きれいな景色を見ながら休憩しよう。
Kirei na keshiki o minagara kyūkei shiyō.
Let’s take a rest while looking at the beautiful scenery.
Unlike i-adjectives, na-adjectives don’t have well-defined dictionary form. They can follow a wide range of patterns, for example:
Type | Example |
|---|---|
“kango” | 元気 genki energetic, cheerful, healthy |
“wago” | にぎやか nigiyaka lively |
きれい kirei beautiful, clean | |
foreign-origin words written in katakana | ユニーク yuniiku unique, unusual |
Want some tips for how you can tell whether an adjective that ends in い[i] is an i-adjective or a na-adjective? Jump to the end of the article where we discuss this question in more detail.
同じ[onaji](same, identical) is an irregular adjective. It conjugates mostly like a na-adjective, but doesn’t take “na” before a noun.
✅同じ人
onaji hito
the same person
❌同じな人
onajina hito
In Japanese, we inflect or adjectives when they are used to form an adjective sentence. These are sentences that you would translate into English using “be” + adjective.
この寿司はおいしい
Kono sushi wa oishii
This sushi is delicious.
When an adjective is conjugated, it changes its form to reflect the tense (past vs. non-past), politeness (plain vs. polite), and polarity (positive vs. negative) of the sentence. But the conjugation pattern will be a bit different depending on whether you’re using an i-adjectives or a na-adjective. Let’s have a look!
There are several different correct ways to form the negative conjugation of adjectives in Japanese, so if the forms below don’t match the negative forms you learned in school, don’t worry! All these ways of forming negation are used by native Japanese speakers, so you will be understood, regardless of which form you use.
For those who are curious, we have prepared alternative conjugation charts so that you can see all the possible negative forms.
To conjugate an i-adjective in the plain form, remove the ending い[i], and replace it with the endings outlined below, depending on the and whether the verb is positive or negative. To form the polite form, simply add です[desu] to the plain form.
Form | Plain form | Polite form |
|---|---|---|
Non-past affirmative: | 暑い atsui | 暑いです atsui desu |
Past affirmative | 暑かった atsukatta | 暑かったです atsukatta desu |
Non-past negative | 暑くない atsukunai | 暑くないです atsukunai desu |
Past negative | 暑くなかった atsukunakatta | 暑くなかったです atsukunakatta desu |
Here’s an example sentence:
昨日は暑かったですが、今日はあまり暑くないですね。
Kinō wa atsukatta desu ga, kyō wa amari atsukunai desu ne.
It was hot yesterday, but it’s not very hot today, isn’t it!
You may notice that the negative ending of adjectives sound similar to the plain negative ending of :
Negative adjectives | Negative verbs |
|---|---|
暑くない atsukunai isn’t hot | 見ない minai don’t look |
暑くなかった atsukunakatta wasn’t hot | 見なかった minakatta didn’t look |
This is because ない[nai] itself is an i-adjective that means “not having” or “not existing”! It works as an auxiliary adjective in adjective conjugation and as an auxiliary verb in verb conjugation. Either way, they conjugate and mean the same (i.e., negation). That’s why the negative endings of adjectives and verbs sound similar in the plain form!
To conjugate a na-adjective, you’ll add the endings directly to the dictionary form. The endings here are a bit more complicated, as you won’t use the same ending for polite forms throughout the conjugation.
Form | Plain form | Polite form |
|---|---|---|
Non-past affirmative: | きれいだ kirei da | きれいです kirei desu |
Past affirmative | きれいだった kirei datta | きれいでした kirei deshita |
Non-past negative | きれいじゃない kirei ja nai | きれいじゃありません kirei ja arimasen |
Past negative | きれいじゃなかった kirei ja nakatta | きれいじゃありませんでした kirei ja arimasendeshita |
In formal speech or writing, では[de wa] is often used instead of じゃ[ja] in all the negative forms. The meaning is the same.
Form | Plain form | Polite form |
|---|---|---|
Non-past negative (formal) | きれいではない kirei de wa nai | きれいではありません kirei de wa arimasen |
Past negative (formal) | きれいではなかった kirei de wa nakatta | きれいではありませんでした kirei de wa arimasendeshita |
Here are some examples:
大学の寮はきれいですか。
Daigaku no ryō wa kirei desu ka.
Is your dormitory at university clean?
いいえ、あまりきれいじゃありません。
Iie, amari kirei ja arimasen.
No, it’s not very clean.
日本語のテスト、どうだった？
Nihongo no tesuto, dō datta?
How was the Japanese test?
わりと簡単だったよ。
Warito kantan datta yo.
It was relatively easy.
You may notice that na-adjective sentences look a lot like “noun sentences”— sentences that consist of “noun + da/desu,” as in:
学生です
gakusei desu
I’m a student
Because of this similarity, na-adjectives have often been called adjectival nouns (nouns that are used as adjectives).
However, there is one big difference between nouns and adjectival nouns: how you use them to answer yes-no questions. When answering a yes-no question about a noun, you usually don’t need to repeat the noun, but when you answer a yes-no question about a na-adjective, you should repeat that adjective. Let’s compare:
Noun Sentences | Adjective Sentences | |
|---|---|---|
Question | ジョンさんは学生ですか。 Jon san wa gakusei desu ka. Is John a student? | その寿司はおいしいですか。 Sono sushi wa oishii desu ka. Is that sushi tasty? |
“Yes” Answer | ええ、そうです。 Ē, sō desu. Yes, he is. | ❌ええ、そうです。 Ē, sō desu. Is that sushi tasty? ✅ええ、おいしいです。 Ē, oishii desu. Yes, it is tasty. |
“No” Answer 1 | いいえ、そうじゃありません。 Iie, sō ja arimasen. Yes, he is. | ❌いいえ、そうじゃありません。 Iie, sō ja arimasen. ❌いいえ、違います。 Iie, chigaimasu. ✅いいえ、おいしくないです。 Iie, oishikunai desu. No, it is not tasty. |
“No” Answer 2 | いいえ、違います。 Iie, chigaimasu. No, he is not. |
In Japanese, 連体詞[rentaishi] are a group of adjectives that cannot be used to form adjective sentences and can only be used before the noun they modify. In English, you might hear them called “adnominal adjectives” or “pre-noun adjectives.”
大きな猫
ōkina neko
large cat
おかしな顔
okashina kao
funny face
ある所
aru tokoro
certain place
小さな犬
chiisana inu
small dog
ほんの一口
hon no hitokuchi
just a bite
その人
sono hito
that person
Adnominal adjectives can only be used before the noun, and cannot be conjugated at the end of a sentence.
✅縄文杉はとても 大きな 木です。
Jōmonsugi wa totemo ōkina ki desu.
The jōmon cedar is a very large tree.
❌縄文杉はとても 大きなです。
Jōmonsugi wa totemo ōkina desu.
The jōmon cedar is very large.
Luckily, though, many adnominal adjectives have a “partner” adjective with basically the same meaning that is a regular i-adjective and can be used at the end of a sentence. For example:
Adnominal Adjective | i-adjective | Translation |
|---|---|---|
大きな ōkina | 大きい ōkii | big, large |
小さな chiisana | 小さい chiisai | small, little |
おかしな okashina | おかしい okashii | funny |
So where you cannot use the adnominal member of the pair at the end of a sentence, it’s just fine to use the i-adjective version:
❌縄文杉はとても大きなです。
Jōmonsugi wa totemo ōkina desu.
The jōmon cedar is very large.
✅ 縄文杉はとても 大きいです。
Jōmonsugi wa totemo ōkii desu.
The jōmon cedar is very large.
Though we can generally use these pairs interchangeably meaning-wise, there is a subtle difference. The i-adjective versions sound a little more objective or analytical while the rentaishi versions sound more emotive and gentle. For this reason, the rentaishi versions are more likely to appear in children’s stories or personal essays than business reports or academic papers. We can definitely use them in everyday conversations!
To ask “what kind” of noun something is in Japanese, you can use the question word どんな[don’na](what kind of) before a noun. To answer, a question like this, simply replace どんな[don’na] with the form of the adjective you use before a noun.
狆はどんな犬ですか。
Chin wa don’na inu desu ka.
What kind of dog is a Japanese spaniel?
おとなしい犬です。
Otonashii inu desu.
They are docile dogs.
渋谷はどんな街ですか。
Shibuya wa don’na machi desu ka.
What kind of town is Shibuya?
にぎやかな街です。
Nigiyakana machi desu.
It’s a lively town.
To ask how something or someone is or was, we can use the question word どう[dō] or its polite version いかが[ikaga]. Questions like these are typically answered with adjective sentences.
沖縄旅行はいかがでしたか。
Okinawa ryokō wa ikaga deshita ka.
How was your trip to Okinawa?
とても楽しかったです。
Totemo tanoshikatta desu.
It was so much fun.
We’ve covered the basics, so let’s give you some tips that will help you learn and use Japanese adjectives.
As we saw above, all i-adjectives end with い[i], but some na-adjectives also end in い[i]. So how can you tell which ones are actually na-adjectives?
Luckily, there aren’t that many na-adjectives that end with い[i]. For beginners, then, the simplest way to remember which adjectives that end in い[i] are actually na-adjectives is to memorize them along with な[na].
Here are some useful “i”-ending na-adjectives to remember. At N5 level of the Japanese Language Proficiency Test (JLPT), you can probably get by with just the first four.
Hiragana | Kanji | Romaji | Meaning |
|---|---|---|---|
きれい[な] | 綺麗[な] | kirei[na] | beautiful, pretty, clean |
きらい[な] | 嫌い[な] | kirai[na] | to dislike, to hate |
ゆうめい[な] | 有名[な] | yūmei[na] | famous |
しんぱい[な] | 心配[な] | shinpai[na] | worried, worrisome |
ていねい[な] | 丁寧[な] | teinei[na] | polite, courteous, careful |
いっしょうけんめい[な] | 一生懸命[な] | isshōkenmei[na] | with heart and soul, hard (work) |
とくい[な] | 得意[な] | tokui[na] | proud, good, strong |
いがい[な] | 意外[な] | igai[na] | surprising, unexpected |
ゆうがい[な] | 有害[な] | yūgai[na] | harmful |
Once you reach a more advanced level, the kanji can also give you a hint. Recall that the い[i]ending on i-adjectives is actually an ending on the stem, so it’s not part of the adjective itself. This means that when we write i-adjectives in kanji “i” is not part of the reading of the kanji.
On the other hand, the “i” on na-adjectives is part of the stem and so it is included in the pronunciation of the kanji (as you can see above!). The only exception is 嫌い[kirai], a na-adjective that is one of the Japanese-origin words.
The i-adjectives いい[ii] and よい[yoi], which both mean “good” or “nice,” differ only in the non-past affirmative forms. In all other forms they are identical. The adjective いい[ii] is more casual and more commonly used in everyday Japanese.
Form | Plain form | Polite form | ||
|---|---|---|---|---|
Non-past affirmative | いい ii | よい yoi | いいです ii desu | よいです yoi desu |
Past negative (formal) | よかった yokatta | よかったです yokatta desu | ||
Non-past negative | よくない yokunai | よくないです yokunai desu | ||
Past negative | よくなかった yokunakatta | よくなかったです yokunakatta desu | ||
For example:
日本語能力試験の１級に合格しました！
Nihongo nōryoku shiken no ikkyū ni gōkaku shimashita!
I passed the level N1 of the Japanese Language Proficiency Test!
わあ、よかったですね。おめでとうございます！
Wā, yokatta desu ne. Omedetō gozaimasu!
Wow, that’s great! Congratulations!
lit. It was good, wasn’t it! Congratulations!
ねえ、そっちの天気はどう ？
Nē, socchi no tenki wa dō?
Hey, how's the weather down there?
昨日はよくなかったけど、今日はいいよ。
Kinō wa yokunakatta kedo, kyō wa ii yo.
It was not good yesterday, but it’s good today.
In this post, we explored the basic facts on Japanese adjectives. Here is a quick summary of the differences between i-adjectives and na-adjectives:
i-adjectives | ||
|---|---|---|
Before a noun | dictionary form | |
Before a noun | Non-past affirmative | い / いです i / i desu |
Past affirmative | かった / かったです katta / katta desu | |
Non-past negative | くない / くないです kunai / kunai desu | |
Past negative | くなかった / くなかったです kunakatta / kunakatta desu | |
na-adjectives | ||
|---|---|---|
Before a noun | dictionary form + な[na] | |
Adjective sentence | Non-past affirmative | だ / です da / desu |
Past affirmative | だった / でした datta / deshita | |
Non-past negative | じゃない / じゃありません ja nai / ja arimasen | |
Past negative | じゃなかった / じゃありませんでした ja nakatta / ja arimasendeshita | |
Ready to practice what you learned? Check out our Japanese adjective activities. Or, if you’d like to review the alternative negative conjugations, check out our Japanese adjective conjugation reference sheet. Happy learning!
