11.2 Adjective Conjugation
In this module, we’ll explore how to vividly describe nouns and express qualities using three groups of adjectives: i-adjectives, na-adjectives and irregular adjectives
Introduction to adjectives
So far in this textbook, we’ve used some common adjectives, like いい (ii: good) in short expressions such as いいですね. In this module, we’ll dive deeper into adjectives and explore the grammatical rules for using different types of adjectives in sentences.
Adjectives are essential for bringing your conversations to life by describing nouns and expressing qualities. In Japanese, they come in three main groups:
1. I-adjectives
2. Irregular i-adjectives
3. Na-adjectives
Let’s explore how to use them in sentences.
Types of adjectives
In Japanese grammar, adjectives are categorised into three groups: i-adjectives, irregular i-adjectives and na-adjectives.
1. I-adjectives
These adjectives are called ‘i-adjectives’ because they end in い (i).
Examples:
おいしい (oishii: delicious/tasty)
面白（おもしろ）い (omoshiroi: interesting/funny)
新（あたら）しい (atarashii: new)
かわいい (kawaii: cute)
2. Irregular i-adjectives
Some i-adjectives are considered irregular because they don’t follow the typical conjugation patterns of standard i-adjectives. Yes, in Japanese, adjectives can be conjugated! We’ll cover adjective conjugation later in this module. The most common irregular i-adjectives are:
いい (ii: good)
かっこいい (kakkoii: good-looking/cool)
NOTE: Originally derived from the adjective よい (yoi), いい and かっこいい have unique conjugations that differ from regular i-adjectives, which will be shown later in this module.
3. Na-adjectives
These adjectives are called ‘na-adjectives’ because they often require the particle な (na) when directly modifying a noun.
Examples:
きれいな (kireina: beautiful/clean)
しずかな (shizukana: quiet)
元気（げんき）な (genkina: healthy/energetic)
Usage in sentences
Adjectives in Japanese are used in two ways:
- Modifying nouns
- Forming basic sentence patterns such as ‘X は (wa) Y です (desu)’
Modifying nouns
1. I-adjectives
I-adjectives directly precede nouns without the need for a particle.
Examples:
- 新（あたら）しいお店（みせ） (atarashii omise: new shop)
明日（あした）、新しいお店に行（い）きます。
Ashita, atarashii omise ni iki masu.
I will go to a new shop tomorrow.
- 大（おお）きい犬（いぬ） (ookii inu: big dog)
大きい犬が好（す）きです。
Ookii inu ga suki desu.
I like big dogs.
2. Irregular i-adjectives
Irregular i-adjectives also directly precede nouns without a particle.
Examples:
- いい人（ひと） (ii hito: a good person)
お店のオーナーはとてもいい人です。
Omise no oonaa wa totemo ii hito desu.
The owner of the shop is a very nice person.
3. Na-adjectives
Na-adjectives require the particle な before nouns.
Examples:
- きれいな公園（こうえん） (kireina kouen: a beautiful park)
ここはとてもきれいな公園ですね。
Koko wa totemo kireina kouen desu ne.
This is a very beautiful park.
- 元気な子（こ）ども (genkina kodomo: energetic child)
元気な子どもがたくさんいます。
Genkina kodomo ga takusan i masu.
There are many energetic/lively children.
‘X は Y です’ sentence pattern
1. I-adjectives
- Affirmative sentences:
Simply add です to the i-adjective. - Negative sentences:
Remove the い from the i-adjective and add くない (kunai) before です. - Questions:
To form a question, simply add the particle か (ka) at the end of either an affirmative or negative sentence.
Examples:
このお店は高（たか）いです。
Kono omise wa takai desu.
This shop is expensive.
このお店は高くないです。
Kono omise wa taka kunai desu.
This shop is not expensive.
このお店は高いですか。
Kono omise wa takai desu ka.
Is this shop expensive?
NOTE: 高い can also mean ‘high’ or ‘tall’, depending on the context.
2. Irregular i-adjectives
The adjective いい is conjugated as よくない in the negative. This is also extended to related adjectives such as かっこいい, which is conjugated as かっこよくない in the negative. Note that かわいい is not an irregular i-adjective; it’s a regular i-adjective, despite ending with いい. Therefore, the negative form of かわいい is かわいくない, not かわよくない.
- Affirmative sentences:
いい remains as is, but the original form よい may be used in more formal contexts. - Negative sentences:
いい becomes よくない (yokunai). - Questions:
As with regular i-adjectives, simply add か at the end of the sentence.
Examples:
それはいいです。
Sore wa ii desu.
That’s good.
それはよくないです。
Sore wa yokunai desu.
That’s not good.
それはいいですか。
Sore wa ii desu ka.
Is that good?
3. Na-adjectives
- Affirmative sentences:
Remove な and add です. - Negative sentences:
Remove な and add じゃない (janai) before です. - Questions:
To form a question, simply add the particle か at the end of either an affirmative or negative sentence.
Examples:
元気です。
Genki desu.
I’m well.
今日（きょう）はあまり元気じゃないです。
Kyou wa amari genki janai desu.
I’m not very well today.
元気ですか。
Genki desu ka.
Are you well?
This table summarises how i-adjectives, irregular i-adjectives and na-adjectives are conjugated in affirmative, negative and question forms in Japanese sentences.
| Type | Affirmative | Negative | Question |
|---|---|---|---|
| i-adjectives | Simply add です | Remove い and add くないです | Simply add ですか |
| irregular i-adjectives | Simply add です | Replace いい with よくないです | Simply add ですか |
| na-adjectives | Remove な and add です | Remove な and add じゃないです | Remove な and add ですか |
Exercise 1
