Mastering です and だ: The Japanese Copula

です and だ are the Japanese equivalents of “is/am/are”. Choosing between them sets the tone of your speech — polite or casual — so it is worth getting right early.

です — the polite form

Use です in most everyday and formal situations: 学生です (I am a student), これはペンです (this is a pen). Its past form is でした, and its negative is ではありません / じゃないです.

だ — the casual form

だ is used in casual speech and writing: 学生だ. Among friends, だ is often dropped entirely (学生？). Its negative is じゃない and its past is だった.

When to use which

• です — with teachers, strangers, customers, elders, and in the workplace.
• だ / plain form — with close friends and family.

Examples

• 田中さんは先生です。 — Mr Tanaka is a teacher. (polite)
• 昨日は休みでした。 — Yesterday was a holiday. (polite past)
• これ、いいね。 — This is nice. (casual, だ dropped)

A beginner tip

When in doubt, use です. It is always safe and polite, and you will never offend anyone with it. As you gain exposure to casual speech, you will learn when だ and the plain form are appropriate.

Speak politely with confidence

Mozhippattru drills polite speech from day one, in Tamil. Book a free demo.