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