な-Adjectives in Japanese – Forms, Conjugation, and How They Work

After learning い-adjectives (like 高い, 安い), the next essential piece of Japanese grammar is な-adjectives.

These adjectives are super common, like 元気(genki) or 静か(shizuka), but the way they work is a little different.

In this guide, we’ll cover:

• Whatな-adjectives are and how to spot them
• How to use them in sentences
• How to make polite, negative, and past forms
• Real examples from daily conversation

Let’s break it down.

What Areな-Adjectives?

な-adjectives are adjectives in Japanese that don’t end inい. Instead, when used before a noun, they need aな in between.

Think of theなas a kind of glue that helps attach the adjective to the noun.

Commonな-adjectives:

• 静か（しずか）– quiet
• きれい– pretty / clean
• 元気（げんき）– healthy / energetic
• 有名（ゆうめい）– famous
• 便利（べんり）– convenient
• 大切（たいせつ）– important

How to Useな-Adjectives

Before a noun

You need な to connect the adjective to the noun:

• 静かなまち → a quiet town
• 元気なこども → a healthy child

At the end of a sentence

Noなneeded — just addです(for politeness):

• この まち は静かです。→ This town is quiet.
• あの こども は元気です。→ That kid is energetic.

How to Conjugateな-Adjectives

Here's how to change them into negative, past, and past-negative forms.

Let’s use 元気 as an example:

1. Present (Affirmative)

• 元気です。→ I’m fine / He’s healthy.

2. Present (Negative)

• 元気じゃないです。→ I’m not fine. (じゃない= casual negative)

You can also say:

• 元気ではありません。→ (more formal/polite)

3. Past (Affirmative)

• 元気でした。→ I was fine.
• 静かでした。→ It was quiet.

4. Past (Negative)

• 元気じゃなかったです。→ I wasn’t fine.
• 静かじゃなかったです。→ It wasn’t quiet.

You can also say:

• 元気ではありませんでした。→ (formal)

じゃないvs.でない— What’s the Difference?

You might notice there's a couple of ways to say "not ~," but they’re used differently depending on tone and formality.

じゃない

• Very common in spoken Japanese
• Becomes polite when you add です (じゃないです)
• Used with な-adjectives and nouns

Examples:

• 元気じゃないです。→ I’m not well.
• ひまじゃなかったです。→ I wasn’t free.

でない（orではない）

• Sounds more formal or written
• Rarely used in daily conversations
• Often replaced by ではありません in polite formal contexts

Examples:

• 元気ではない。→ Not well. (Formal/literary tone)
• 有名ではありません。→ Not famous. (Formal and polite)

So… which should you use?

• Use じゃないです in most polite everyday conversations
• Use ではありません if you’re writing formally or giving a speech
• You might see でない or ではない in books, articles, or anime with a serious tone — but don’t worry about using them yourself just yet

Practice Time!

Try conjugating theseな-adjectives into polite forms:

便利（べんり/ convenient）

• Present:便利です
• Negative:便利じゃないです
• Past:便利でした
• Past Negative:便利じゃなかったです

すてき（suteki / lovely, wonderful）

• Present:すてきです
• Negative:すてきじゃないです
• Past:すてきでした
• Past Negative:すてきじゃなかったです

きれい（kirei / pretty, clean）

Note: Even though it ends inい, it's aな-adjective!

• Present:きれいです
• Negative:きれいじゃないです
• Past:きれいでした
• Past Negative:きれいじゃなかったです

Quick Recap

• な-adjectives don’t end inい
• You need な when they come before a noun
• No な needed when used at the end of a sentence
• To make them negative, use じゃないです
• To make them past, use でした/じゃなかったです