Adjectives 形容詞
An adjective (形容詞) is a word that describes some attribute1 (属性) of a noun. In English, an adjective can either come directly before a noun or modify it from afar as the predicate (part of the sentence which makes a statement about the subject) with the help of a “to be” verb.
i. I sold the old book.
ii. I ate a green apple.
iii. The moose was large.
iv. Textbooks are expensive.
v. The young man bought a new car.
In Japanese, adjectives (形容詞) can modify a noun directly before it (in its attributive form 連体形) or qualify it as the predicate of the sentence (in its predicative form). Unlike English, the copula (だ) does not accompany adjectives (形容詞) in either situation. In fact, inserting だ to mirror the use of “to be/is/are” like in English is ungrammatical. Thus, adjectival predicates (形容詞述語) simply constitute the adjective itself.
To showcase these points, consider the adjective 新しい meaning “new.” This single word can stand for “to be new,” “is new,” “are new,” as Japanese conjugation does not take into account grammatical person2.
1a. （これは）新しい本だ。〇
1b. （これは）新しい（な X・だ X）本だ。
(This is) a new book.
2. この本は新しい。〇
This book is new.
3. この本は新しいだ。X3
This book is new.
Our focus in this lesson will be on how to conjugate said adjectives. Before we get started, though, let’s recap on our grammatical terminology before continuing this discussion!
- Predicate: The part of a sentence that makes a statement about the subject.
- Auxiliary: An ending that helps construct verbal conjugations.
- Adjective: A word that describes an attribute.
- Base: One of the six forms that a conjugable part of speech (verb, adjective, auxiliary verb, etc.) may take which is then followed by endings (auxiliaries, etc.).
- Terminal/Predicative Form: Known in Japanese as the 終止形, it marks the end of a complete sentence/the predicate.
- Attributive Form: Known in Japanese as the 連体形, it is used to make a verb, adjective, etc. into a modifier that goes directly before a noun.
- Basic Form: The basic form of any given phrase, in other words, is utilized in plain speech as well as in many grammatical circumstances. The basic form encompasses both the predicative and the attributive forms in the context of verbs and adjectives.
- Continuative Form: Known in Japanese as the 連用形, it is used with endings pertaining to actions being carried out.
The Basic/Non-Past Form
形容詞の基本形・非過去形
Plain Non-Past Form: No Conjugation
All 形容詞 end in the vowel /i/ い, which has given rise to the name “i-adjectives イ形容詞” in many textbooks. This い attaches to the stem (語幹), and it is subsequently dropped to create all other conjugations.
This “basic form” of adjectives is used for the non-past form (非過去形). Although “non-past” may stand for both the present tense (現在時制) and the future tense (未来時制), in the case of adjectives, it is only interpreted as the present tense unless other grammatical points intervene.
This basic non-past, unconjugated for stands for both the predicative form (終止形) and the attributive form (連体形). This means you may place adjectives before nouns or at the end of the sentence without having to conjugate.
| 形容詞 | Meaning | 形容詞 | Meaning |
| 【熱・暑】い | Hot | 厚い | Thick |
| 辛い | Hot (spicy) | 欲しい | To want |
| 冷たい | Cold | 寒い | Cold (weather) |
| 古い | Old | 若い | Young |
| 明るい | Bright | 暗い | Dark |
| 【暖・温】かい | Warm | 強い | Strong |
| 小さい | Small | 大きい | Large/Big |
| 【早・速】い | Fast/Early | 遅い | Slow/Late |
| 高い | Tall/Expensive | 安い | Cheap |
| 低い | Short/Low | 弱い | Weak |
Vocabulary Notes:
①熱い means “hot” as in things whereas 暑い means “hot” as in the weather. Both are enunciated with a LHL (low-high-low) pitch.
②厚い means “thick” and is enunciated with a LHH (low-high-high) pattern.
③ In addition to meaning “spicy,” 辛い may also mean “salty,” especially for speakers from West Japan. In Standard Japanese, “salty” is expressed with 塩辛い. However, in literary language, it may still mean “salty” if written as 鹹い. Confusingly, the colloquial way to say “salty” in East Japan is しょっぱい.
④As an English speaker, you may be confused as to why 欲しい is in a list of adjectives if it means “to want,” but in Japanese, this word is an adjective.
⑤冷たい means “cold” as in things whereas 寒い means “cold” as in “weather.” 冷たい may also refer to “cold” personalities. What about the air or wind? These are treated as objects and, thus, take 冷たい.
Ex. 冷たい空気 (cold air)
Ex. 冷たい風 (cold wind)
Ex. 表情 (cold expression)
⑥古い refers to the state of a thing/situation being “old,” but it is not used to refer to old age.
⑦暖かい and 温かい are both read as あたたかい. The first spelling is used in reference to the weather whereas the second spelling is used to refer to “warm” to the touch as well as in reference to emotion. In casual speech, it is pronounced as あったかい.
⑧When used to mean “early/quick,” はやい is spelled as 早い. When strictly referring to the speed of an object, it may be spelled as 速い.
⑨When referring to the height of a person, 高い must be used in the set phrase 背が高い.
⑩低い may refer to “low” as in rank, value, quality, position to the ground, etc. Although it may mean “short” as in height, it must be used in the set phrase 背が低い.
1. クマは強い。
Bears are strong.
2. 人間は弱い生き物だ。
Humans are weak creatures.
3. 南米は暑い！
South America is hot!
4. 手が熱い。
My/your hands are hot.
5. あれは古い電話だ。
That is an old phone.
6. 水が冷たい。
The water is cold.
7. 冬は寒い！
Winter is cold!
8. あの店は安い。
That store is cheap (affordable).
9. 彼はいつも返事が遅い。
His responses are always late.
10. あの子はまだ若い。
That kid is still young.
11. 感染抵抗力が弱い動物は発病しやすい。
Animals whose resistance to infection is weak are likely to become ill.
Grammar Note: In Exs. 2 and 11, 弱い is in its attributive form (連体形). In Ex. 11, it is part of a larger clause modifying the noun 動物 (animal): [感染抵抗力が弱い]. The particle が is obligatory here instead of the particle は because the topic of the sentence is the full noun phrase [感染抵抗力が弱い動物]. Grammatically, this whole phrase functions as one big noun, and the attributive form (連体形) of the adjective is the glue that combines what would be a stand-alone sentence to a noun to make that bigger noun. The predicative form (終止形), on the other hand, tells the listener that they have reached the end of the sentence.
Polite Non-Past 非過去の丁寧形
How to make the non-past tense polite is easy yet riddled in controversy. In Modern Japanese, the solution is simply to add ～です after the adjective, using it purely as a politeness marker4 – NOT as a copular verb.
Because this ～です is purely just a politeness marker, it lacks an attributive form (連体形), which means it CANNOT modify a noun even when it is with an adjective. Always expect ～です to be at the end of a sentence.
| Meaning | Plain Speech | Polite Speech (+ ～です) |
| Close/Nearby | 近い | 近いです |
| Far | 遠い | 遠いです |
| Beautiful | 美しい | 美しいです |
| Fun | 楽しい | 楽しいです |
| Painful | 痛い | 痛いです |
| New | 新しい | 新しいです |
Vocabulary Notes:
①近い can be used in both a spatial and temporal sense. It can also be used to refer to “close” relationships and “close” relatives. It may also be used to describe degree. It is also used in the phrase for “to be nearsighted,” which is 目が近い.
②遠い can be used in both a spatial and temporal sense, refer to “distant” relationships and relatives, and “far (from)” in the sense of degree. It can refer to distant sounds and is also used in the phrase for “to be farsighted,” which is 目が遠い.
③痛い means “painful,” but it also is used in situations where English speakers would likely use the verb “to hurt.” It is also the interjection used for “ouch.” Be careful with intonation. It should be pronounced with a LHL intonation. A LHH intonation results in the noun 遺体 meaning “dead body.”
12. 公園が近いです。
The park is nearby.
13. 景色が美しいです。
The scenery is beautiful.
14. 仕事は楽しいです。
(My) work is fun.
15. 足が痛いです！
My feet hurt!
Past Tense 過去形（常体・丁寧体）
To make an adjective past tense in plain speech, drop ～い and add ～かった. This conjugation involves the adjective’s secondary continuative form (連用形) used with auxiliary verbs かり～5 + the past tense auxiliary verb ～た. To make this polite, all you do is add ～です directly onto the predicative form (終止形) of ～かった. Again, this ～です is not the copula, rather, it only functions as a politeness marker.
Just like with the non-past tense, you can only use the plain past form before a noun. NEVER add ～です because it does not have an attributive form (連体形)!
| Meaning | BasIC Form | Plain Past （＋～かった） | Polite Past（＋～かったです） |
| Delicious | おいしい | おいしかった | おいしかったです |
| Bad | まずい | まずかった | まずかったです |
| Kind | 優しい | 優しかった | 優しかったです |
| Strict | 厳しい | 厳しかった | 厳しかったです |
| Wide | 広い | 広かった | 広かったです |
| Narrow | 狭い | 狭かった | 狭かったです |
| Thin | 薄い | 薄かった | 薄かったです |
| Thick | 濃い | 濃かった | 濃かったです |
| New | 新しい | 新しかった | 新しかったです |
Vocabulary Notes:
①When used to mean “delicious,” おいしい may also be spelled as 美味しい. It also has the meaning of “attractive” in the sense of “favorable.”
②まずい means “bad” as in flavor, in which case it may also be spelled as 不味い. When used to mean “bad” as in “unskillful,” it may be spelled as 拙い. It can also refer to “bad/awkward” situations, and in this situation, it is often used in the sense of “oh, no!”
③薄い is “thin” in relation to objects but never people, but it ironically can be used to refer to “thin/slim” chance. It may also refer to colors being “pale” or something being “dilute(d)” in a liquid. From this last meaning it can also mean “weak” as in taste. Think coffee.
④濃い refers to the thickness (depth) of color, the thickness (density) of liquids, or the thickness (strength) of flavors, smells, possibilities, or relationships. Unlike 厚い, it is never used to refer to the thickness of physical objects. Also, most speakers in West and South Japan pronounce this word as 濃ゆい.
16. ラーメンは美味しかったです。
The ramen was delicious.
17. 仕事が忙しかった。
Work was busy.
18. あの映画は楽しかったです。
That movie was fun.
19. 彼が優しかった。
He was kind.
20. 長谷川先生は厳しかったです。
Hasegawa-sensei was strict.
21. 道が狭かったです。
The street(s) were narrow.
22. 元から成功の望みは薄かった。
There was slim hope of success from the start.
23. 病院食はまずかったです。
The hospital meals were awful.
24. 味は若干濃かったです。
The flavor was somewhat strong.
25. （お）弁当が美味しかった話
Talk of the bento having been delicious.
Grammar Note: The prefix お～ is attached to a number of nouns to make them sound politer.
Plain Negative Form w/ ～くない
常体語における否定形
To make the negative (to not be…) form of an adjective, drop ～い and add ～くない. The ～ない part functions as an auxiliary adjective (補助形容詞), meaning it also conjugates like any other adjective, and the ～く is the basic continuative form.
The ～く functions the same as the で in ～ではない. In fact, it is possible to insert the particle は in between ～く and ～ない to give ～くはない, which serves the same purpose.
Grammar Note: The /ku/ continuative form causes adjectives to behave essentially like adverbs, with ～ない being the adjective that is being modified.
| Meaning | Base Form | Negative (Plain)（＋～くない） |
| Thin | 細い | 細くない |
| Thick | 太い | 太くない |
| Difficult | 難しい | 難しくない |
| Cute | かわいい | かわいくない |
| Sad | 悲しい | 悲しくない |
| Happy | 嬉しい | 嬉しくない |
| Scary/Scared | 怖い | 怖くない |
| New | 新しい | 新しくないです |
①細い means “thin” as in “slender” and may be used in reference to people.
②太い means “thick” as in “fat” and may also refer to a person’s voice being “thick.”
③Do not pronounce かわいい the same way as 怖い. They are clearly separate words.
④怖い may translate as “scary” or “scared,” but this is due to the Japanese grammar being simpler than English. The word is only used from a personal perspective, so you yourself are scared of things that are scary.
Negation is not limited to the predicative form (終止形). Meaning, you can use the negative form of an adjective in its attributive form (連体形). There is no change in morphology, but you can see a negative adjective be a part of a much larger dependent clause modifying a noun.
26. 僕は蛇が怖くないよ。
I’m not scared of snakes.
As for me, snakes aren’t scary.
27. あの猫はかわいくはないよ。
That cat isn’t cute (but does fit another description).
28. 僕は悲しくない。
I’m not sad.
29. 操作は難しくない。
Operating it isn’t difficult.
30. 難しくない点もメリットのひとつです。
The point of it not being difficult is also one of its merits.
Polite Negative Forms w/ ～くないです・～くありません
丁寧語における否定形（くないです・くありません）
There are two methods to make an adjective negative in polite speech just like there is for the copula, and the methods are created in the same fashion.
- Method 1: Simply attach ～です to the plain negative form, producing ～くないです. This method is not as polite, but it is still appropriate for general conversation with peers and strangers.
- Method 2: Drop ～い and add ～くありません. This involves replacing ない with its proper polite form, which is ありません. Its derivation will make sense more once we learn about verbs.
Note that it is possible to insert the particle は to demonstrate negative contrast in between ～くand the negation element in either negative form (～くはないです/-～くはありません).
| Meaning | Basic Form | Negative 1（＋～くないです） | Negative 2（＋～くありません） |
| Correct | 正しい | 正しくないです | 正しくありません |
| Blue/green | 青い | 青くないです | 青くありません |
| Red | 赤い | 赤くないです | 赤くありません |
| New | 新しい | 新しくないです | 新しくありません |
Vocabulary Note: 青い may be used in both the sense of “blue” and “green.”
Grammar Note: None of these forms are used in the attributive form because です CANNOT modify nouns.
31. 川は青くはないです。
The river is not blue (but another color would describe the color better).
32. 信号は青くないです。
The light is not green.
33. あのリンゴは赤くありません。
That apple is not red.
34. その答えは正しくないです。
That answer isn’t correct.
35 私は背が低くありません。
I am not short.
Plain Negative-Past Form w/ ～くなかった
常体語における過去の否定形（くなかった）
The simplest way to conceptualize how to make the negative-past in plain speech is to drop ～い and add ～くなかった. However, the true mechanics is simply conjugating the auxiliary adjective ～ない into its past tense form with the same ending as any other adjective, ～かった.
Grammar Note: Showing negative contrast in an adjective phrase simply involves inserting the particle は between ～く and the negation element regardless of tense.
| Meaning | Base Form | Negative (Plain) （＋～くなかった） |
| Sweet | 甘い | 甘くなかった |
| Dirty | 汚い | 汚くなかった |
| Good | 良い | 良くなかった |
| Bad | 悪い | 悪くなかった |
| Black | 黒い | 黒くなかった |
| White | 白い | 白くなかった |
| Brown | 茶色い | 茶色くなかった |
| New | 新しい | 新しくなかった |
Vocabulary Notes:
①甘い may also mean “fragrant” and is generally also treated as the opposite of 辛い. The word may also be figuratively used to mean “tempting,” “half-hearted,” “naive,” etc.
②汚い may also mean “dirty” as in “indecent/vulgar” language as well as “underhanded.”
Grammar Note:
The plain negative-past form may be used in both the attributive form and the predicative form. It is more common to see the negative-past in the attributive form when it is a part of a larger modifying, dependent clause. However, this is not a requirement.
36. このパソコンは安くなかった。
This computer wasn’t cheap.
37. 給料は高くなかった。
The salary wasn’t/wages weren’t high.
38. その城は白くなかった。
That castle wasn’t white.
39．葉っぱは茶色くなかった。
The leaves weren’t brown.
40. タイヤは黒くなかった。
The tire(s) weren’t black.
41. 今回はそこまで甘くはなかった。
This time it wasn’t so sweet like that.
42. 天気はあまり良くなかった。
The weather wasn’t that good.
43. 私の成績が悪かった理由
The reason why my grades were bad
Polite Negative-Past Forms
丁寧語における過去の否定形（～くなかったです・～くありませんでした）
Just as there are two methods for making an adjective negative in polite speech, there are also two methods to conjugating an adjective into negative past (was not) in polite speech.
- Method 1: Simply attach ～です to ～くなかった, giving ～くなかったです.
This method is not as polite, but it is still appropriate for general conversation with peers and strangers. - Method 2: The politer method involves the past tense form of ありません, which is ありませんでした, producing ～くありませんでした.
Its derivation will make sense more once we learn about verbs.
| Meaning | Base Form | Negative 1 （＋～くなかったです） | Negative 2 （＋～くありませんでした） |
| Long | 長い | 長くなかったです | 長くありませんでした |
| Short | 短い | 短くなかったです | 短くありませんでした |
| Sleepy | 眠い | 眠くなかったです | 眠くありませんでした |
| Amazing | 凄い | 凄くなかったです | 凄くありませんでした |
| Dangerous | 危ない | 危なくなかったです | 危なくありませんでした |
| Shallow | 浅い | 浅くなかったです | 浅くありませんでした |
| Deep | 深い | 深くなかったです | 深くありませんでした |
| Light/Faint | 淡い | 淡くなかったです | 淡くありませんでした |
| New | 新しい | 新しくなかったです | 新しくありませんでした |
Vocabulary Notes:
①短い is not “short” as in “height,” but it can be used to mean “short” in most situations.
②If one is really drowsy to the point it is uncomfortable, you may hear the more emphatic 眠たい instead of 眠い. Similarly, the adjective for “heavy” 重い works the same way and can be seen as 重たい if the heaviness is being expressed as being unpleasant or in a way that implies the weight is pressing down.
④浅い may refer to depth in the sense of wounds, color, and knowledge in addition to literal lack of depth.
⑤深い means “deep” but it may also refer to “dense” such as in “dense forest” (深い森) or “dense fog” (深い霧). It may also refer to “deep/close” relationships or “intense” degree.
⑥淡い is mostly limited to expressing faint color, but it can be used in referring to feeling something indistinctly.
Grammar Note: Although this should go without saying, these polite forms do not possess the attributive form because they all involve ～です. So, expect them to only be at the end of the sentence!
44. 試験は短くありませんでした。
The exam was not short.
45. 傷は深くありませんでした。
The wound was not deep.
46. 夜は危なくなかったです。
Nighttime wasn’t dangerous.
In Conclusion 最後に…
In this lesson, we learned how to conjugate adjectives with the understanding that the system is no different to how the copula is conjugated. On top of this, several dozen adjectives tested within the N5 and N4 levels of the Japanese Language Proficiency Test (JLPT) were showcased.
In the next lesson, we will learn about adjectival nouns. These words semantically behave as adjectives, but their conjugation powers rely on using the copula.
- An “attribute” is a defining characteristic that specifies some value of the word it is modifying – size, color, shape, smell, outlook, or any other extrinsic property of the word in question. ↩︎
- In languages like English with “grammatical person,” conjugations must agree with who is talking/being discussed – ex. “I am tall” vs “you are tall” vs “he/she/it is tall.” In Japanese, conjugations will never change based on this. ↩︎
- In dialects throughout the Tohoku Region, Ex. 3 is not ungrammatical. However, in Standard Japanese, the copula だ must never follow an adjectival predicate. ↩︎
- This grammar has only been around for a little over a century, but it has fully replaced the older grammar, which we will eventually get to when we learn about honorific speech, that would otherwise take its place. ↩︎
- Adjectives actually have two continuative forms: the /kari-/ form and the /ku-/ form. The かり～ form is actually a contraction of the basic one く～ + the existential verb ある. In most dictionaries, the かり～ form is rendered as かっ～ because of how it contracts with the past tense auxiliary verb ～た. ↩︎