Nouns & the Copula (です / だ)
Learning Objectives
- Understand the concept of the Copula (the 'to be' verb).
- Distinguish between Polite (です) and Plain (だ) speech styles.
- Form Affirmative and Negative sentences using nouns.
- Express Past Tense for nouns (was / was not).
In English, the most common verb in the world is “to be” (I am, you are, it is). It links a subject to a noun or adjective (“I am a student”). In Japanese, this grammatical link is called the Copula.
Unlike English, where the verb changes based on the subject (I am vs He is), the Japanese copula changes based on Tense (Present vs Past) and Politeness (Who you are talking to). Let’s learn how to politely declare, deny, and describe things using the Japanese copula: です (desu).
1. Present Affirmative: “Is / Am / Are”
To declare that A is B, you simply place the topic (A) followed by the particle は, then the noun (B), and end the sentence with the copula です (desu).
[!TIP] Polite vs. Plain Form Japanese has two main speaking styles. Polite Form (です/ます form) is used with strangers, superiors, or in formal situations. Plain Form (Dictionary form) is used with close friends, family, or casual situations. In this chapter, we focus on Polite Form, but we will introduce the plain equivalents so you recognize them. The plain form of です is だ (da).
わたし は がくせい です。
Watashi wa gakusei desu.
I am a student. (Polite)
これ は くるま だ。
Kore wa kuruma da.
This is a car. (Plain/Casual)
せんせい は アメリカじん です。
Sensei wa Amerika-jin desu.
The teacher is American.
2. Present Negative: “Is Not / Am Not / Are Not”
To say that A is not B, you change the ending. The polite negative of です is じゃありません (ja arimasen).
[!NOTE] In writing or very formal speeches, you might see ではありません (dewa arimasen). In casual speech, the plain form is じゃない (ja nai).
わたし は いしゃ じゃありません。
Watashi wa isha ja arimasen.
I am not a doctor. (Polite)
きょう は げつようび じゃない。
Kyou wa getsuyoubi ja nai.
Today is not Monday. (Plain/Casual)
あのひと は エンジニア じゃありません。
Ano hito wa enjinia ja arimasen.
That person is not an engineer.
3. Past Affirmative: “Was / Were”
To talk about the past (A was B), change です to でした (deshita).
きのう は あめ でした。
Kinou wa ame deshita.
Yesterday was rain. (Polite)
むかし、がくせい だった。
Mukashi, gakusei datta.
In the past, I was a student. (Plain/Casual)
せんしゅう は やすみ でした。
Senshuu wa yasumi deshita.
Last week was a holiday/break.
4. Past Negative: “Was Not / Were Not”
This is the longest form! To combine the Past tense with the Negative tense (A was not B), you use じゃありませんでした (ja arimasen deshita).
きのう は どようび じゃありませんでした。
Kinou wa doyoubi ja arimasen deshita.
Yesterday was not Saturday. (Polite)
にほんご は かんたん じゃなかった。
Nihongo wa kantan ja nakatta.
Japanese was not easy. (Plain/Casual)
あのひと は せんせい じゃありませんでした。
Ano hito wa sensei ja arimasen deshita.
That person was not a teacher.
Common Noun Vocabulary (Professions & Time)
| Word | Romaji | Meaning | Type |
|---|---|---|---|
| がくせい | Gakusei | Student | Noun |
| せんせい | Sensei | Teacher | Noun |
| いしゃ | Isha | Doctor | Noun |
| かいしゃいん | Kaishain | Company Employee | Noun |
| エンジニア | Enjinia | Engineer | Noun |
| きょう | Kyou | Today | Noun (Time) |
| あした | Ashita | Tomorrow | Noun (Time) |
| きのう | Kinou | Yesterday | Noun (Time) |
| むかし | Mukashi | In the past / Old times | Noun (Time) |
Conversation Practice
はじめまして。たなか です。かいしゃいん です。
Hajimemashite. Tanaka desu. Kaishain desu.
Nice to meet you. I am Tanaka. I am a company employee.
はじめまして、スミス です。アメリカじん です。たなかさん は エンジニア ですか。
Hajimemashite, Sumisu desu. Amerika-jin desu. Tanaka-san wa enjinia desuka?
Nice to meet you, I am Smith. I am American. Are you an engineer, Mr. Tanaka?
いいえ、エンジニア じゃありません。わたし は いしゃ です。
Iie, enjinia ja arimasen. Watashi wa isha desu.
No, I am not an engineer. I am a doctor.
そう ですか！むかし、わたし の ちち も いしゃ でした。
Sou desuka! Mukashi, watashi no chichi mo isha deshita.
Is that so! In the past, my father was also a doctor.
わたし の あに は いしゃ じゃありませんでした。がくせい でした。
Watashi no ani wa isha ja arimasen deshita. Gakusei deshita.
My older brother was not a doctor. He was a student.
Chapter Summary
- 1The Copula links a subject to a noun. It changes based on Tense and Politeness.
- 2Present Affirmative: です (desu). Plain form: だ (da)
- 3Present Negative: じゃありません (ja arimasen). Plain form: じゃない (ja nai)
- 4Past Affirmative: でした (deshita). Plain form: だった (datta)
- 5Past Negative: じゃありませんでした (ja arimasen deshita). Plain form: じゃなかった (ja nakatta)
Knowledge Check
Test your ability to conjugate nouns using the four forms of the copula!
Quiz
Which of the following creates a polite PRESENT AFFIRMATIVE sentence (A is B)?