Japanese Adjectives
Master the Two Types of Adjectives and Their Grammar
Table of Contents
1. Overview & Types
Japanese has TWO types of adjectives: I-adjectives (ending in い) and Na-adjectives (ending in な when modifying nouns)
Each type follows different conjugation rules and grammar patterns
Adjective System Overview
I-Adjectives (形容詞): True adjectives that end in い and conjugate like verbs
Na-Adjectives (形容動詞): Adjectival nouns that use な to modify nouns
Conjugation: Both types change form for tense, politeness, and negation
Function: Describe qualities, states, and characteristics of nouns
2. I-Adjectives (形容詞)
Big
Basic Form
Past Form
Small
Basic Form
Past Form
Hot
Basic Form
Past Form
Cold
Basic Form
Past Form
New
Basic Form
Past Form
Old
Basic Form
Past Form
I-Adjective Characteristics
Ending: Always end in い (but not all words ending in い are i-adjectives)
Conjugation: Change the い ending to other forms
Independence: Can stand alone as predicates
Modification: Directly modify nouns without particles
3. Na-Adjectives (形容動詞)
Beautiful
Modifying Noun
Predicate
Quiet
Modifying Noun
Predicate
Convenient
Modifying Noun
Predicate
Famous
Modifying Noun
Predicate
Na-Adjective Characteristics
Base Form: Usually written in kanji or katakana
Modification: Add な when modifying nouns
Predicate: Use です/だ when used as predicate
Origin: Many are borrowed from Chinese or other languages
4. Conjugation Patterns
I-Adjective Conjugations
| Form | Pattern | Example (大きい) | English |
|---|---|---|---|
| Present Positive | 〜い | おおきい | big / is big |
| Present Negative | 〜くない | おおきくない | not big |
| Past Positive | 〜かった | おおきかった | was big |
| Past Negative | 〜くなかった | おおきくなかった | was not big |
| Te-form | 〜くて | おおきくて | big and… |
Na-Adjective Conjugations
| Form | Pattern | Example (きれい) | English |
|---|---|---|---|
| Present Positive | 〜だ / 〜です | きれいだ / きれいです | beautiful / is beautiful |
| Present Negative | 〜ではない / 〜ではありません | きれいではない | not beautiful |
| Past Positive | 〜だった / 〜でした | きれいだった / きれいでした | was beautiful |
| Past Negative | 〜ではなかった | きれいではなかった | was not beautiful |
| Te-form | 〜で | きれいで | beautiful and… |
5. Common Adjectives
Essential I-Adjectives
| Japanese | Romaji | English | Antonym |
|---|---|---|---|
| 高い | takai | high, expensive | 低い (hikui) / 安い (yasui) |
| 長い | nagai | long | 短い (mijikai) |
| 面白い | omoshiroi | interesting | つまらない (tsumaranai) |
| 難しい | muzukashii | difficult | 易しい (yasashii) |
| 美味しい | oishii | delicious | まずい (mazui) |
| 忙しい | isogashii | busy | 暇 (hima – na-adj) |
Essential Na-Adjectives
| Japanese | Romaji | English | Antonym |
|---|---|---|---|
| 元気 | genki | healthy, energetic | 病気 (byouki) |
| 親切 | shinsetsu | kind | 意地悪 (ijiwaru) |
| 大変 | taihen | difficult, terrible | 簡単 (kantan) |
| 安全 | anzen | safe | 危険 (kiken) |
| 大切 | taisetsu | important | – |
| 暇 | hima | free time | 忙しい (isogashii – i-adj) |
6. Comparison & Degrees
Comparative Forms
More than (より):
Aは Bより おおきいです。
A is bigger than B.
Most (いちばん):
Aが いちばん おおきいです。
A is the biggest.
As…as (ほど):
Aは Bほど おおきくないです。
A is not as big as B.
Degree Modifiers
| Modifier | Romaji | Meaning | Example |
|---|---|---|---|
| とても | totemo | very | とても大きい |
| 少し | sukoshi | a little | 少し寒い |
| かなり | kanari | quite, considerably | かなり難しい |
| ちょっと | chotto | a bit | ちょっと高い |
| すごく | sugoku | extremely (casual) | すごく面白い |
7. Position in Sentences
Attributive Position (Modifying Nouns)
I-Adjectives:
大きい 車
big car
Na-Adjectives:
きれいな 花
beautiful flower
Predicate Position (End of Sentence)
I-Adjectives:
この車は 大きいです。
This car is big.
Na-Adjectives:
この花は きれいです。
This flower is beautiful.
8. Irregular Adjectives
Special Cases
| Adjective | Type | Special Note | Example |
|---|---|---|---|
| いい / よい | I-adjective | Irregular conjugation | よかった (past), よくない (negative) |
| きれい | Na-adjective | Ends in い but is na-adjective | きれいな人 |
| 嫌い | Na-adjective | Ends in い but is na-adjective | 嫌いな食べ物 |
| 有名 | Na-adjective | Written in kanji | 有名な人 |
いい (Good) – The Most Irregular
Present: いい or よい (both mean “good”)
Past: よかった (was good)
Negative: よくない (not good)
Past Negative: よくなかった (was not good)
Usage: いい is more common in conversation, よい in formal writing
9. Advanced Usage
Adjective + そう (Looks like…)
I-Adjectives (drop い, add そう):
美味しそう – looks delicious
面白そう – looks interesting
Na-Adjectives (add そう):
元気そう – looks healthy
便利そう – looks convenient
Multiple Adjectives
Using て-form to connect:
大きくて きれいな 家
a big and beautiful house
新しくて 便利で 安い 車
a new, convenient, and cheap car
Nominalization
| Pattern | Usage | Example | English |
|---|---|---|---|
| Adj + の | Noun substitute | 赤いのが好きです | I like the red one |
| Adj + こと | Abstract concept | 早いことが大切です | Being fast is important |
10. Practice & Examples
Common Sentence Patterns
Describing People:
田中さんは 親切な 人です。
Tanaka-san is a kind person.
Describing Objects:
この本は とても 面白いです。
This book is very interesting.
Past Experience:
昨日は 暑かったです。
Yesterday was hot.
Question Patterns
| Question | Response | English |
|---|---|---|
| どうですか？ | いいです / よくないです | How is it? / It’s good / not good |
| どんな人ですか？ | 親切な人です | What kind of person? / A kind person |
| どちらが大きいですか？ | こちらの方が大きいです | Which is bigger? / This one is bigger |
Memory Tips
I-Adjective Recognition: If it ends in い and can conjugate, it’s probably an i-adjective
Na-Adjective Clues: Often written in kanji, borrowed words, or end in な when modifying
Conjugation Practice: Start with common adjectives like 大きい and きれい
Context Usage: Pay attention to whether the adjective modifies a noun or stands alone
Common Mistakes to Avoid
Don’t add です to i-adjectives twice: ❌ 大きいです ✅ 大きいです
Don’t forget な with na-adjectives: ❌ きれい人 ✅ きれいな人
Don’t mix up similar endings: きれい (na-adj) vs. きたない (i-adj)
Remember irregular いい: Past is よかった, not いかった
Adjective Mastery Achieved!
You’ve learned the fundamental grammar of Japanese adjectives! Now you can describe people, objects, and situations with confidence using both i-adjectives and na-adjectives.
Adjectives Quiz
Test Your Knowledge of Japanese Adjective Grammar
Exercise 1: Adjective Types
What type of adjective is 大きい?
Explanation: 大きい (ookii) ends in い and conjugates like a verb, making it an i-adjective.
Exercise 2: Past Tense
What is the past tense of 寒い (cold)?
Explanation: I-adjectives form past tense by changing い to かった.
Exercise 3: Na-Adjective Recognition
Which of these is a na-adjective?
Explanation: Despite ending in い, きれい is a na-adjective. It uses な when modifying nouns.
Exercise 4: Negative Form
How do you make 面白い (interesting) negative?
Explanation: I-adjectives form negative by changing い to くない.
Exercise 5: Modifying Nouns
How do you say “quiet person” using 静か?
Explanation: Na-adjectives need な when modifying nouns.
Exercise 6: Irregular Adjective
What is the past tense of いい (good)?
Explanation: いい is irregular and changes to よ- forms in conjugation.
Exercise 7: Te-form Connection
How do you connect two adjectives: “big and beautiful”?
Explanation: Use the te-form (くて for i-adjectives, で for na-adjectives) to connect adjectives.
Exercise 8: Comparison
How do you say “A is bigger than B”?
Explanation: Use より (yori) to express “more than” in comparisons.
Exercise 9: Degree Modifier
Which modifier means “very”?
Explanation: とても means “very.” 少し means “a little,” ちょっと means “a bit.”
Exercise 10: Na-adjective Past
What is the past tense of 元気 (healthy/energetic)?
Explanation: Na-adjectives use でした for polite past tense, like nouns with the copula.
Exercise 11: Appearance (そう)
How do you say “looks delicious” using 美味しい?
Explanation: Drop い from i-adjectives and add そう to express “looks like.”
Exercise 12: Superlative
How do you say “the most interesting”?
Explanation: いちばん before an adjective creates the superlative form.
Exercise 13: Common Mistake
Which sentence is INCORRECT?
Explanation: Na-adjectives must use な when modifying nouns. The correct form is きれいな花.
Exercise 14: Polite Forms
Which is the polite form of 高い (expensive)?
Explanation: I-adjectives become polite by adding です (not changing the adjective itself).
Exercise 15: Question Formation
How do you ask “What kind of person is he/she?”
Explanation: どんな asks “what kind of” and is perfect for asking about characteristics.
How did you do?
Check your answers by selecting options above. Each correct answer will show in purple!
In Japanese grammar, adjectives play an important role in describing people, objects, and situations. There are two main types: words ending with -i and words used with na. Each type follows different rules for past tense, negative form, and polite speech. Learning how to use them correctly helps beginners understand daily conversations and express ideas more naturally. Mastering these forms is an essential step for anyone studying Japanese language.
