Japanese Adjective Usage

Japanese has two classes of adjectives that conjugate differently. 形容詞 (keiyoushi), literally "qualifying words", are often called -i or verb-like adjectives (this term is also used to describe English adjectives). 形容動詞 (keiyoudoushi), literally "qualifying movement words", are often called -na or noun-like adjectives.

A third adjective category called 連体詞 (rentaishi), literally "attributive words", must always come before a noun. The category contains a mix of things that may look more like verbs (such as いわゆる), pronouns (such as あの), or -na adjectives (such as 大きな) unless you're a linguist. More importantly, they don't conjugate, so I won't mention them very often.

There's also another category of noun-like adjectives that use たる (taru) instead of な (na) to link with nouns, and と (to) instead of に (ni) when acting as adverbs, but these -taru adjectives have mostly died out and are very rare in modern Japanese.

Arguably, none of these are properly "adjectives" in the English sense of the word, especially since -i adjectives act a lot like verbs and -na adjectives are nearly the same thing as nouns. But since they're usually used to modify nouns, "adjective" is probably the best English can do to describe them, so that's what they're generally called, and that's what I'm going with. Adjectives can be used several different ways.


Attributive Usage

This is when an adjective directly precedes the noun it modifies, like "cold weather" or "healthy person". -i adjectives are placed before their nouns in dictionary form; -na adjectives are the same but include the ~な (-na). Any of the conjugated short forms may also be used.

Except in the case of rentaishi, which cannot end a sentence and must always be used attributively, this is just a special case of sentences modifying nouns, where the sentence is just an adjective. Yes, a single word can be a complete sentence in Japanese!

On a bit of a side note, the ~な (na) of -na adjectives is derived from the なる (naru), short for にある (ni aru), copula of classical Japanese. This is not typically relevant to modern Japanese except that ~なる is sometimes used in place of ~な for effect.

Also, certain classical ~なる adjectives have evolved into rentaishi (non-conjugating adjectives) in modern Japanese, but since these are fixed phrases that always contain the なる, they shouldn't cause any problems. A typical example is 単なる (tan naru).

With pronouns

In English, adjectives cannot directly modify pronouns such as I, you, them, and it. Japanese has no such qualms, and is prefectly willing to attach adjectives, and other descriptive phrases, directly to pronouns. This, unsurprisingly, tends to complicate translation, typically resulting in either a clunky "[pronoun] that is [adjective]" phrase or, usually preferably, rewording the sentence to capture the essense more naturally.


Conjugations

This is where -i adjectives look a lot like verbs and -na adjectives look just like nouns. The forms mean the same thing as for verbs. To use these, simply put the noun with the appropriate adjective form in a sentence like so: [noun]は[adjective] ([noun] wa [adjective]). Alternately, put one of the short forms right before the noun, as explained above. It means the same as [noun] is/isn't/was/wasn't/etc. (depending on the form used) [adjective]. So, for example...

So here's the chart. D stands for dictionary form, and that's without the ~な for -na adjectives.

There is one sort-of exception: The -i adjective いい (ii) is actually a variant of よい (yoi), and conjugates as よい in all forms except nonpast affirmative. So the past affirmative casual is よくない (yokunai), the -te form is よくて (yokute), and so on.

Other than that, all adjectives conjugate regularly. Examples are included on the chart.

FormAdjectiveLongShort
Nonpast
Affirmative
-i adjectivesD + です (desu)D
新しい (atarashii)新しいです (atarashii desu)新しい (atarashii)
-na adjectivesD + です (desu)D, optionally + だ (da).
D + な when modifying a noun
賑やか (nigiyaka)賑やかです (nigiyaka desu)賑やか(だ) (nigiyaka (da))
賑やかな[noun]
Nonpast
Negative
-i adjectivesD - い + くありません (ku arimasen)
or D - い + くないです (ku nai desu)
D - い + くない (ku nai)
詰らない (tsumaranai)詰らなくありません (tsumaranaku arimasen)
or 詰らなくないです (tsumaranaku nai desu)
詰らなくない
(tsumaraku nai)
-na adjectivesD + じゃありません (ja arimasen)
or D + じゃないです (ja nai desu)
D + じゃない (ja nai)
きれい (kirei)きれいじゃありません (kirei ja arimasen)
or きれいじゃないです (kirei ja nai desu)
きれいじゃない
(kirei ja nai)
Past
Affirmative
-i adjectivesD - い + かったです (katta desu)D - い + かった (katta)
小さい (chiisai)小さかったです (chiisakatta desu)小さかった (chiisakatta)
-na adjectivesD + でした (deshita)D + だった (datta)
元気 (genki)元気でした (genki deshita)元気だった (genki datta)
Past
Negative
-i adjectivesD - い + くありませんでした (ku arimasen deshita)
or D - い + くなかったです (ku nakatta desu)
D - い + くなかった
(ku nakatta)
熱い (atsui)熱くありませんでした (atsuku arimasen deshita)
or 熱くなかったです (atsuku nakatta desu)
熱くなかった
(atsuku nakatta)
-na adjectivesD + じゃありませんでした (ja arimasen deshita)
or D + じゃなかったです (ja nakatta desu) (uncommon)
D + じゃなかった
(ja nakatta)
暇 (hima)暇じゃありませんでした (hima ja arimasen deshita)
or 暇じゃなかったです (hima ja nakatta desu) (uncommon)
暇じゃなかった
(hima ja nakatta)
Affirmative
-te Form
-i adjectivesD - い + くて (kute)
かわいい (kawaii)かわいくて (kawaikute)
-na adjectivesD + で (de)
親切 (shinsetsu)親切で (shinsetsu de)
Negative
-te Form
-i adjectivesD - い + くなくて (ku nakute)
大きい (ookii)大きくなくて (ookiku nakute)
-na adjectivesD + じゃなくて (ja nakute)
大変 (taihen)大変じゃなくて (taihen ja nakute)
Affirmative
Conditional
-i adjectivesD - い + かったら (kattara)
よろしい (yoroshii)よろしかったら (yoroshikattara)
-na adjectivesD + だったら (dattara)
馬鹿 (baka)馬鹿だったら (baka dattara)
Negative
Conditional
-i adjectivesD - い + くなかったら (ku nakattara)
いい (ii)よくなかったら (yoku nakattara)
-na adjectivesD + じゃなかったら (ja nakattara)
愚か (oroka)愚かじゃなかったら (oroka ja nakattara)
Affirmative
Provisional
-i adjectivesD - い + ければ (kereba); D + なら (nara) is similar
面白い (omoshiroi)面白ければ (omoshirokereba); 面白いなら (omoshiroi nara) is similar
-na adjectivesD + であれば (de areba); D + なら (nara) is similar
素直 (sunao)素直であれば (sunao de areba); 素直なら (sunao nara) is similar
Negative
Provisional
-i adjectivesD - い + くなければ (ku nakereba); D - い + くないなら (ku nai nara) is similar
古い (furui)古くなければ (furuku nakereba); 古くないなら (furuku nai nara) is similar
-na adjectivesD + じゃなければ (ja nakereba); D + じゃないなら (ja nai nara) is similar
変 (hen)変じゃなければ (hen ja nakereba); 変じゃないなら (hen ja nai nara) is similar
Alternative Anythe appropriate past tense + り (ri)
長い (nagai) 長かったり (nagakattari) if positive
長くなかったり (nagaku nakattari) if negative
鮮やか (azayaka) 鮮やかだったり (azayaka dattari) if positive
鮮やかじゃなかったり (azayaka ja nakattari) if negative

Also note that an adjective can end in い (i) and still be a -na adjective rather than an -i adjective. The standard example is きれい (kirei), which can also be written in kanji as 奇麗, though it generally isn't due to the complexity of the characters. Note that the い is part of the kanji and not a trailing character, as it is in -i adjectives like 黒い (kuroi), for example.


High Formality

Adjectives also have highly formal variants. For -na adjectives, this is simple; just use the highly polite copula, でございます (de gozaimasu) instead of the usual です (desu). For -i adjectives, it's more complicated.

DictionaryVery Polite
next to last kana has an a vowel change final ai to ou and add ございます (gozaimasu)
next to last kana has an i vowel change final ii to yuu and add ございます (gozaimasu)
next to last kana has an u vowel change final ui to uu and add ございます (gozaimasu)
next to last kana has an o vowel change final oi to ou and add ございます (gozaimasu)
Examples:
早い (hayai)早うございます (hayou gozaimasu)
かわいい (kawaii)かわゆうございます (kawayuu gozaimasu)
嬉しい (ureshii)嬉しゅうございます (ureshuu gozaimasu)
大きい (ookii)大きゅうございます (ookyuu gozaimasu)
眠い (nemui)眠うございます (nemuu gozaimasu)
遅い (osoi)遅うございます (osou gozaimasu)

These may also be preceded with the honorific お (o). Certain idiomatic phrases such as お早うございます (ohayou gozaimasu), which functions as "good morning" but is literally just "it is early" phrased very politely, come from this form.


Seems... Looks like... (-sou ending)

To say how something seems, drop the final い (i) for -i adjectives, leave out the な (na) for -na adjectives, and add そう (sou) to what's left. The result is a -na adjective. It indicates that whatever you are referring to seems to be or looks like the adjective you started with, when you don't have enough information to be sure. As such, そう is rarely used with adjectives such as "pretty" that depend on perception, since it's difficult to imagine a situation in which you could tell that something seems to be pretty without being able to say that it actually is pretty.

When using そう with negatives, create the negative form as usual, then change the final ~ない (-nai) to ~なさそう (-nasasou).

Finally, for whatever reason, いい (ii) becomes よさそう (yosasou), not いそう (isou) or よそう (yosou).

Also refer to the related clause endings みたい (mitai) and よう (you).

The adverbial form—add に (ni) as explained in the "as other parts of speech" section below—is fairly common with certain adjectives and may be used in ways that are not intuitive to English speakers, or at least don't translate cleanly.

"Eats hungrily" is a reasonable approximation in this particular case.


Observations about other people (-gatte iru)

Some adjectives, such as かわいい (kawaii, roughly translating to cute) can be used as-is when describing other people, but others refer to things such as personal feelings that an outside observer can never be quite sure of. Adjectives of this type include 嬉しい (ureshii = happy), 痛い (itai = painful), and the ~たい (-tai) verb ending, which indicates a desire. To talk about other people, the tendency is to be more indirect, perhaps by saying that they said they want to, or that you think they want to. Another way, for -i adjectives of this type, is to drop the final い and add ~がる (-garu) or ~がっている (-gatte iru), meaning that your observations of the person's behavior indicate this conclusion.

The adjective 欲しい (hoshii), meaing wanted or wished for, often acts like this and is normally used as [object]が欲しい ([object] ga hoshii). However, when making an observation of want with ~がっている, use を (wo) instead of が (ga).


Too Much (-sugiru)

To express the idea of "too much", add the auxiliary verb ~すぎる (-sugiru). For -i adjectives, first drop the final い (i); for -na adjectives, just leave out the な (na). すぎる is a -ru verb and conjugates as such.

Referring to someone or something with adjective + すぎる has a negative connotation. You wouldn't normally, for example, say that someone is 楽しすぎる (tanoshisugiru = too much fun), unless you're suggesting that this is a bad thing in some way, such as being so much fun that you didn't get any sleep all weekend and now you're dead on your feet.


Somewhat (-me)

To moderate an -i adjective, similar to using the English ending "-ish", replace the final ~い (-i) with ~め (-me) and use the result as a -na adjective. As usual, the adverbial form also applies. This usage might apply only to certain adjectives, and there doesn't seem to be an equivalent for -na adjectives at all.


As Other Parts of Speech

Nouning adjectives

-i adjectives can be used as abstract nouns by replacing the ending い (i) with さ (sa), though this doesn't apply to all adjectives. The resulting noun refers to the attribute that the adjective describes.

You can do the same with some -na adjectives by adding さ (sa), but this seems to be somwhat less common.

-na adjectives are sometimes used directly as nouns, especially in colloquial speech, though perhaps they technically shouldn't be.

Adverbing adjectives

All adjectives have a corresponding adverbial form. -i adjectives change the final い (i) to く (ku), while -na adjectives add に (ni).

As noted in the introduction, -taru adjectives use と (to) instead of に (ni).

Verbing Adjectives

Adjectives can be used like verbs with a few changes. Make the adverbial form (above), and add なる (naru) to mean "become [adjective]", or する (suru) to mean "make [adjective]".

Notice that there's no way to tell a relative change (becoming more than it was before) from an absolute one (wasn't before but is now). Looking the first example above, if the change is absolute, then the store had not been busy before, but now is. If the change is relative, then the store may or may not have been busy at first, but is now more busy than it had been. In other words, 忙しくなった (isogashiku natta) could mean either "get busy" or "get busier". The intended meaning can be clarified by context, and there are several simple ways to make the type of change explicit.

より (yori) by itself also works, though that leaves some ambiguity as to what it's more than. Then again, English "busier" (to keep the same example) has the same ambiguity, and how often does anyone care?

Additionally, -na adjectives such as 好き (suki) that seem like verbs are sometimes used as verbs in colloquial speech, even though this isn't considered correct usage.

For what it's worth, the proper usage is 「週末好き」 (shuumatsu ga suki), with "weekend" marked as the subject.