JLPT N5 Grammar: だ / です (da / desu)

Q: When do I use だ instead of です?

Use だ in casual situations – with close friends, family, or informal writing. です is the polite form for strangers and formal contexts.

Q: Can I put だ after an い-adjective?

No. い-adjectives already contain the meaning of 'is'. Say おいしい (casual) or おいしいです (polite), never おいしいだ.

Q: Is きれいだ correct?

Yes, because きれい is a な-adjective, so きれいだ (casual) and きれいです (polite) are both correct.

Q: What's the negative form of です?

じゃありません or ではありません (polite negative). Casual negative is じゃない.

The Copula: "is / am / are" in Japanese – Plain & Polite

JLPT N5 文法だ・です解説

Master だ / です in 5 minutes. Learn the most fundamental Japanese grammar — how to say something "is" politely or casually, and avoid the #1 beginner mistake.

🚀 Quick JLPT N5 Warm-up Quiz

Q1: "This is delicious." Which is correct?
A. これはおいしいだ
B. これはおいしいです

Answer: B (い-adjectives do NOT take だ; they can take です for politeness, or stand alone)

Quick Summary

Grammar Point
だ / です

Meaning
Is / am / are (copula)

Usage
Noun + だ / です
な-adj + だ / です
い-adj + ❌ だ / です ✅

Example
犬いぬです。いぬです。 Inu desu.
It's a dog.

📝 Quick Formula

Noun + だ / です

な-adjective (stem) + だ / です

い-adjective → NO だ! Use alone or add です for politeness

Not confident with adjectives yet?
Review い vs な adjectives →

💡 Switch to Hiragana only or Rōmaji if you're just starting out.

What is だ / です?

だ and です are the Japanese equivalents of "is", "am", or "are" — the copula that links a subject to a noun or adjective. They indicate that something is something.

です → polite form. Use with strangers, superiors, in most public situations.
だ → plain/casual form. Used with close friends, family, or in informal writing.
い-adjectives already contain the meaning of "is". You never add だ after them (❌おいしいだ). For politeness, add です directly (おいしいです).

日本語にほんごの基本きほんです。にほんごのきほんです。 Nihongo no kihon desu.

How to Pronounce

です： de su (the "u" is nearly silent)

だ： da

いぬです / ねこだ / きれいです

Examples & Mini Dialogue

犬いぬです。いぬです。 Inu desu.
It's a dog. (noun + です)

Polite statement. In casual speech: 犬だ.

静しずかだ。しずかだ。 Shizuka da.
It's quiet. (な-adj + だ, casual)

Polite: 静かです.

美味おいしいです。おいしいです。 Oishii desu.
It's delicious. (い-adj + です, polite)

Never おいしいだ. Casual: おいしい (drop です).

🗣️ Mini Dialogue
A: これは何なんですか。これはなんですか。 Kore wa nan desu ka.
B: 本ほんです。ほんです。 Hon desu.
("What is this?" — "It's a book.")

When to Use in Real Japan

Self-introduction: 私わたしはアヌプです。わたしはアヌプです。Watashi wa Anupu desu.
Identifying things: それは猫ねこだ。それはねこだ。Sore wa neko da.
Describing with な-adj: 便利べんりですね。べんりですね。Benri desu ne.

⚡ だ vs です vs である — Levels of Formality

These three copulas are used in different contexts. JLPT N5 focuses on だ and です.

Form	Politeness	Example
だ	Plain / casual	猫だ。 (It's a cat.)
です	Polite	猫です。
である	Formal / written	猫である。 (literary)

💡 Exam tip: On the N5, you'll mostly need です for polite answers and だ for recognizing casual speech in listening.

Common Mistakes

✕ おいしいだおいしいだOishii da

✓ おいしい / おいしいですおいしい / おいしいですOishii / oishii desu
(い-adjectives never take だ!)

🔍 Why? い-adjectives already function as predicates. Adding だ is redundant and ungrammatical.

✕ 静しずかですだしずかですだShizuka desu da

✓ 静しずかですしずかですShizuka desu
(Never mix です and だ)

🔍 Use one or the other: 静かだ (casual) or 静かです (polite).

🎌 JLPT N5 Exam Trick

The test often asks you to choose the correct sentence:

「このケーキは (　　　)。」
A. おいしいです
B. おいしいだ

Answer: A. Remember: い-adj + だ = ❌.

JLPT N5 Practice Questions

1. "That is a cat." (casual)
A. あれは猫だ
B. あれは猫ですだ

Show Answer

Correct: A (猫 + だ)

2. "It is quiet." (polite, 静か = quiet, な-adj)
A. 静かです
B. 静かだです

Show Answer

Correct: A (な-adj stem + です)

3. Choose the correct sentence:
A. この花はきれいだ
B. この花はきれいです

Show Answer

Both are correct! A is casual, B is polite. (きれい is a な-adj, so both だ and です are acceptable.)

⚠️ The い-adjective + だ mistake is one of the quickest ways to lose N5 points.

Eliminate it with targeted practice.
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About the Instructor

This lesson is taught by Anup Sensei, an experienced Japanese language instructor at Gogaku Language & Training Center in Pokhara. He has studied and worked in Japan and specializes in practical JLPT preparation and real-life communication skills.

Frequently Asked Questions

When do I use だ instead of です?

Use だ in casual situations – with close friends, family, children, or in informal writing. です is the safe polite form for strangers and formal settings.

Can I put だ after an い-adjective?

No. おいしいだ is incorrect. い-adjectives already contain the copula meaning; just say おいしい (casual) or add です for politeness.

Is きれいだ correct?

Yes, because きれい is a な-adjective, not an い-adjective. So きれいだ (casual) and きれいです (polite) are both correct.

What's the negative form of です?

じゃありません / ではありません. Example: 犬じゃありません (It is not a dog). Casual: じゃない.

Continue Learning

Now master the past tense of です:
でした / だった (was / were)

Learn でした / だった →

→ Explore the full JLPT N5 Grammar Hub

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