Japanese Grammar Fundamentals: Introduction to Adjectives

Adjectives are words that describe the properties of nouns.  These can include general descriptors such as numbers (five cats, ごひきねこ [go-hiki no neko]), colors (blue flowers, あおはな [aoi hana]), or other qualities that help provide more information about the item which is being described.

Japanese has two primary groups of adjectives: I-adjectives and NA-adjectives.  Let’s take a quick look at both.

Identifying an Adjective’s Type

To determine if an adjective is really an I-adjective, the most reliable way is to look at how it is written in kanji.

  • I-adjectives will always have okurigana 1: 〜い (-i) in most cases, though 〜しい (-shii) is also common for adjectives with emotional connotations and 〜ない (-nai) appears occasionally as well.  Examples include:
    • い (ii, good)
    • わるい (warui, bad)
    • うれしい (ureshii, happy)
    • うつくしい (utsukushii, beautiful)
    • すくない (sukunai, scarce)
    • あぶない (abunai, dangerous)
  • NA-adjectives often do not have okurigana.  When they do, however, it is most often one of 〜か (-ka), 〜やか (-yaka), or 〜らか (-raka) due to reasons stemming from Classical Japanese2.  No NA-adjective ending in い (i) has okurigana, however, as demonstrated3 in the following examples:
    • きれい (kirei, neat/pretty)
    • ぶれい (burei, rude/impolite)
    • しぜん (shizen, natural)
    • しずか (shizuka, quiet)
    • あきらか (akiraka, clear/unambiguous)
    • やすらか (yasuraka, peaceful)
    • すみやか (sumiyaka, prompt/speedy)

い (I) Adjectives

I-adjectives take their name from the fact that, without exception, they all end in the syllable い (i).  That said, as we demonstrated above, not all adjectives that end in い (i) are in this group.

In practice, I-adjectives behave in a similar manner to verbs.  They can accept many of the same endings4, and in casual speech they even replace the be-verb だ・です (da/desu) at the end of declarative sentences.

For example, if you just tried some takoyaki5 and loved the taste of it, you might exclaim the following:

Formal Informal
Kono takoyaki wa oishii desu!
This takoyaki is delicious!
Kono takoyaki wa oishii!
This takoyaki is delicious!

Using I-Adjectives

When adjectives appear directly beside a noun, Japanese grammar places the adjective first (as it works in English).  In the case of I-adjectives, you just place them right next to each other:

adjective + noun

  • あおそら (aoi sora, blue sky)
  • たかビル (takai biru, tall building)
  • はやでんしゃ (hayai densha, fast train)

Similar to English, it is also possible to move the adjective to the predicate (second half of the sentence), where it describes the noun subject of the sentence.  This typically takes the format:

subject/noun + + adjective + です6

  • あのそらあおです。 (Ano sora wa aoi desu.  “That sky is blue.”)
  • このビルはたか! (Kono biru wa takai! “This building is tall!”)
  • このでんしゃはやですか? (Kono densha wa hayai desu ka? “Is this train fast?”)

な (NA) Adjectives

NA-adjectives derive their name from the fact that when used immediately before a noun you are supposed to add the particle な (na)7: きれいひと (kirei na hito, beautiful person)

Whereas I-adjectives behave like verbs, NA-adjectives behave like nouns.  だ・です (Da/desu) is always required when a NA-adjective appears at the end of a sentence, even in informal speech, since the adjective is unable to accept endings on its own.  Consider the following examples:

Present Tense Past Tense
Koko wa kiken desu.
It is dangerous here.
Koko wa kiken deshita.
It was dangerous here.

Using NA-Adjectives

As we mentioned earlier, the defining feature of NA-adjectives is the use of the particle between an adjective and its associated noun when the two are placed adjacent to each other:

adjective + + noun

  • とくべつレッスン (tokubetsu na ressun, special lesson)
  • みょうにおい (myou na nioi, strange smell)
  • しぜんやりかた (shizen na yarikata, natural way of doing things)

There are many cases where NA-adjectives form the base for compound words.  In these cases, the な (na) is typically omitted.

As with I-adjectives, it is also possible to move the adjective to the predicate (second half of the sentence), where it describes the noun subject of the sentence.  The format remains unchanged in this case, except that だ (da) is added to the end of the sentence in informal speech8:

subject/noun + + adjective + だ・です

  • あのそらあおです。 (Ano sora wa aoi desu.  “That sky is blue.”)
  • このビルはたか! (Kono biru wa takai! “This building is tall!”)
  • このでんしゃはやですか? (Kono densha wa hayai desu ka? “Is this train fast?”)

の (NO) Adjectives

NO-adjectives are a lesser (and somewhat contested) classification of adjectives in Japanese which function very similarly to NA-adjectives, except that where NA-adjectives would use the particle な (na) before a noun, NO-adjectives use の (no) instead.

The reason for the change in particle (and why some people don’t consider these true adjectives) is that NO-adjectives are nouns which have been repurposed to function as adjectives.

For example, many colors (any that end in 〜いろ [iro]), the word refers to the color itself.  Let’s perform a quick comparison between the colors brown (ちゃいろ chairo) and blue (あおい aoi) to help demonstrate the way they behave differently.9

Used as an Adjective Used as a Noun
Ano chairo no hon wa sugoku tanoshii.
That brown book is very entertaining.
Chairo ga suki desu ka?
Do you like [the color] brown?
Ano aoi hon wa sugoku tanoshii.
That blue book is very entertaining.
Ao ga suki desu ka?
Do you like [the color] blue?

In both examples, you’ll notice that ちゃいろ (chairo, brown) remained unchanged, other than that we added の (no) when it was placed right before a noun.

あおい (aoi, blue), on the other hand, is an I-adjective.  To use it as a noun, we need to do something about the ending.  For colors, it’s a simple as dropping the 〜い (-i) at the end.  For other I-adjectives we may need to replace 〜い (-i) with another ending (typically either 〜さ [-sa] or 〜み [-mi])10.

The Placeholder Pronoun の (No)

Pronouns are words that are used in place of nouns to avoid having to awkwardly repeat full names or specifics.  の (No) is used in place of a noun to refer to an object previously mentioned in the conversation.

For example, let’s look at a hypothetical conversation between two people who are out clothes shopping:

Dono sukaato ga hoshii?
Which skirt do you want?
Sono aoi no.
That blue one.

The first person is asking which item the second person wants (in this case, from a selection of skirts they’ve been looking at).  Since we’ve already established that we’re talking about skirts, the second person uses の (no) in place of スカート (sukaato) when answering the question.

Bonus topic: Colors!

This has been quite a busy lesson so far!  Let’s review the most commonly-used colors quickly to provide some adjectives to start practicing with.

  • あおい (aoi) I-adjective blue
  • あかい (akai) I-adjective red
  • ちゃいろ (chairo) NO-adjective brown
  • きいろ (kiiro) NO-adjective yellow
  • ももいろ (momoiro) NO-adjective pink
  • くろい (kuroi) I-adjective black
  • しろい (shiroi) I-adjective white
  • オレンジ (orenji) NO-adjective orange
  • はいいろねずみいろ (haiiro/nezumi iro) NO-adjective gray

Are there any adjectives you’d like to know how to say in Japanese?  Ask in the comments!


In order of appearance.  Words that only appear in footnotes are at the end of the list.

  • (go) five
  • ひき (-hiki) counter for four-legged animals (is attached to the number of animals being counted)
  • ねこ (neko) cat
  • あおい (aoi) blue
  • はな (hana) flower
  • おくがな (okurigana) Kana that are added to kanji characters to help form words.  Often added to provide the endings for verbs or adjectives.
  • い (ii) good
  • わるい (warui) bad
  • うれしい (ureshii) happy
  • うつくしい (utsukushii) beautiful
  • すくない (sukunai) few
  • あぶない (abunai) dangerous
  • きれい (kirei) neat, pretty, beautiful, clean
  • ぶれい (burei) rude, impolite
  • しぜん (shizen) natural (e.g. behavior)
  • しずか (shizuka) quiet
  • あきらか (akiraka) clear, unambiguous
  • やすらか (yasuraka) peaceful
  • すみやか (sumiyaka) prompt, speedy
  • だ (da) casual form of です (to be)
  • です (desu) to be
  • たこき (takoyaki) octopus balls
  • おいしい (oishii) tasty, delicious
  • そら (sora) sky
  • たかい (takai) high, tall, expensive
  • ビル (biru) building
  • はやい (hayai) fast, quick
  • でんしゃ (densha) [electric] train
  • ひと (hito) person
  • ここ (koko) here
  • きけん (kiken) dangerous
  • とくべつ (tokubetsu) special
  • レッスン (ressun) lesson
  • みょう (myou) strange
  • におい (nioi) smell, scent
  • やりかた (yarikata) way of doing something
  • いろ (iro) color
  • ちゃいろ (chairo) brown (literally, “tea color”)
  • ほん (hon) book
  • すごい (sugoi) great, amazing
  • たのしい (tanoshii) entertaining, fun
  • スカート (sukaato) skirt
  • しい (hoshii) desired
  • あかい (akai) red
  • きいろ (kiiro) yellow (literally, “yellow color”)
  • ももいろ (momoiro) pink (literally, “peach color”)
  • くろい (kuroi) black
  • しろい (shiroi) white
  • オレンジ (orenji) orange
  • はいいろ (haiiro) gray (literally, “ash color”)
  • ねずみいろ (nezumi iro) gray (literally, “mouse color”)
  • おもしろい (omoshiroi) amusing, entertaining
  • あたたかい (atatakai) warm


Thanks for checking out our introduction to Japanese adjectives!  If this is your first time visiting the site, you can check out the first lesson in our Japanese Grammar Fundamentals series here.

As always, if you have any suggestions on how to improve things or topics you would like to see us cover, feel free to drop a note in the comments!

Next week we’re going to do a formal introduction to Japanese verbs, allowing you to start unlocking the full potential of the language.  See you then!

  1. Extra kana surrounding the kanji, most often at the end of a word, often for purposes of adding endings to words
  2. A topic for a later post
  3. To the extent one can prove a negative
  4. We will address adjective endings alongside verb endings as we introduce them in later lessons
  5. Octopus balls!  Read more on Wikipedia
  6. Remember, leave です off in casual speech
  7. Etymologically, this な (na) is derived from Classical Japanese なり (nari), which is an archaic form of だ・です (da/desu).  The closest analogue, if you were to try and translate it literally, would be to the effect of “the noun which is adjective
  8. There are some nuances to this which shall be addressed in later lessons as they arise.
  9. I’m having trouble coming up with a good NA-adjective to use in this comparison, but if someone has an example, feel free to drop it in the comments!
  10. Per DAIJIRIN, 〜さ (-sa) is for when something you’re talking about a state, condition, or something that can be measured.  〜み (-mi) refers to a state or condition resembling that which the adjective describes.

    For example, おもしろい (omoshiroi) means “fun/amusing”, while おもしろさ (omoshirosa) refers to the degree to which something is entertaining.  あたたかい (atatakai) means “warm”, while あたたかみ (atatakami) refers to warmth in an abstract sense.

Kanji Usage Data

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Paul Baptist

Paul Baptist

Japanese linguist, web developer, bassist, teacher, and long-time anime fan.

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