What is です?
です is the Japanese copula. It works like "is," "am," or "are" in English. When you say 学生です (gakusei desu), you're saying "I am a student." Simple as that.
But here's the thing: Japanese has multiple levels of formality, so "to be" isn't just one word. It's a whole family. In casual speech you'll hear だ (da), in polite conversation です (desu), and in very formal or customer-service settings でございます (de gozaimasu). They all mean the same thing. The difference is who you're talking to and how polite you need to be.
Unlike English, です doesn't change based on the subject. Whether it's "I am," "you are," or "they are," the Japanese stays the same. No conjugation for person or number. Just for tense and politeness. Our lesson on basic sentence structure walks through です and ます in real sentences from scratch.
One quick note: です only attaches to nouns and na-adjectives. For i-adjectives, you don't need a copula (おいしい already contains the "is" meaning). Adding です to i-adjectives is purely for politeness, not grammar. See our adjective conjugation guide for more on how い and な adjectives work with です.
Conjugation Table
| Plain | Polite | Very Polite | |
|---|---|---|---|
| Present (is) | だ (da) | です (desu) | でございます (de gozaimasu) |
| Negative (is not) | じゃない (ja nai) | じゃありません (ja arimasen) / ではありません (dewa arimasen) | ではございません (dewa gozaimasen) |
| Past (was) | だった (datta) | でした (deshita) | でございました (de gozaimashita) |
| Negative Past (was not) | じゃなかった (ja nakatta) | じゃありませんでした (ja arimasen deshita) | ではございませんでした (dewa gozaimasen deshita) |
| Presumptive (probably is) | だろう (darou) | でしょう (deshou) | でございましょう (de gozaimashou) |
When to Use だ vs です
This trips up a lot of learners. Here's the breakdown:
Use だ with close friends, family, people younger than you, and in your own internal thoughts. It's also the form you'll see in written prose, news, and academic writing.
Use です with strangers, coworkers, teachers, older people, and anyone you want to show basic respect to. This is your safe default in most daily interactions.
Use でございます in customer service, formal announcements, business emails to clients, or when speaking to someone of significantly higher status. You'll hear it constantly in shops and hotels.
One important exception: in casual speech, men often end sentences with だ, but women and younger speakers sometimes drop it entirely. Saying きれいだ sounds a bit blunt; きれい by itself or きれいだね feels more natural in conversation.
Example Sentences
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彼は医者です。 (kare wa isha desu.) — He is a doctor.
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これは何だ？ (kore wa nan da?) — What is this? (casual)
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会議は三時からでございます。 (kaigi wa sanji kara de gozaimasu.) — The meeting is from 3 o'clock. (very polite)
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昨日は休みだった。 (kinou wa yasumi datta.) — Yesterday was a day off.
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あの店は有名じゃなかった。 (ano mise wa yuumei ja nakatta.) — That shop wasn't famous.
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明日は雨でしょう。 (ashita wa ame deshou.) — It will probably rain tomorrow.
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原因はストレスだろう。 (gen'in wa sutoresu darou.) — The cause is probably stress.
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こちらが出口でございます。 (kochira ga deguchi de gozaimasu.) — This way is the exit. (very polite, like a hotel staff member)