Conjugations of the Japanese Copula

This page covers the basic conjugations of the copula in plain (informal), polite (formal), and honorific form. You should at last be familiar with the polite copula です (desu) before continuing, and knowing a bit about verb conjugation and honorific speech will help you get the most out of this page.

Recommended Background:

The Copula “Desu”

Politeness and Formality in Japanese

Basic Forms of the Copula

A copula is a word meaning “to be”, and is used to predicate a sentence, giving the subject identity, properties, state, or membership in a group. Unlike in English, however, the Japanese copula can’t be used to show existence – instead you must use the verbs いる (iru) for animate beings and ある (aru) for inanimate objects.

The copula takes three basic forms in standard speech: the plain form だ (da) in informal speech, the polite form です (desu) in formal speech, and でございます (de gozaimasu) in honorific speech. In the case of the last form, the same word is used both for respectful and humble speech; unlike other components of keigo, de gozaimasu is neutral to who the subject is.

In truth, things are a little more complicated than this. You should be at least aware of de aru and de arimasu, the literary forms of da and desu respectively. This is also where de gozaimasu fits into the picture – de gozaru is the honorific form of de aru, but with keigo the polite form of an honorific verb is almost always used, so we get de gozaimasu. And yes, it is no coincidence that these look just like the existential verb aru and its polite and honorific forms.

Basic Conjugations of the Copula

In the following chart, conjugations are given for each of the three major forms of the copula, and in some cases more that one form will be given. Verb conjugations for which the copula has no equivalent are left out, execept in cases where a particle is used instead. Forms used only in writing and other obscure forms are also omitted.

Basic Conjugations of the Copula
	Plain	Polite	Honorific
Present Affirmative	だ da	です desu	でございます de gozaimasu
Past Affirmative	だった datta	でした deshita	でございました de gozaimashita
*Present Negative	では/じゃ　ない de wa nai （じゃない ja nai）	では/じゃ　ありません dewa/ja arimasen **では/じゃ　ないです dewa/ja nai desu	ではございません dewa gozaimasen
*Past Negative	では/じゃ　なかった dewa/ja nakatta	では/じゃ　ありませんでした dewa/ja arimasen deshita  **では/じゃ　なかったです dewa/ja nakatta desu	ではございませんでした dewa gozaimasen deshita
Volitional	だろう darou	でしょう deshou	（でございましょう de gozaimashou）
Te-Form	で de	（でありまして de arimashite）	（でございまして de gozaimashite）
Conditional	なら/ならば nara/naraba	（であれば de areba)	（であれば de areba)
Attributive	***の/な no/na	–	–

*In the negative forms, ja is a colloquial contraction of de wa.
**Replacing arimasen with nai desu expresses a stronger negation.
***The attributive form of the copula is de aru, but the particles no and na are generally used instead. This no is the familiar modifying particle, but in some cases na is used instead (such as the “explaining” construction na no da/desu).

The last three rows are mid-sentence constructions, so the plain form is generally used. However, derivatives of the polite and honorific forms are occasionally used for the te-form and conditional form. In general, very formal speech has more similarities to the written language than everyday speech does.

Written Forms

In written Japanese, you will encounter the base forms de aru and de arimasu and their conjugations more frequently.

The Copula in Written Japanese
	Plain		Polite
Present Affirmative	だ da	である de aru	です desu	であります de arimasu
Past Affirmative	だった datta	であった de atta	でした deshita	でありました de arimashita
*Present Negative	ではない dewa nai		ではありません dewa arimasen
			ではないです dewa nai desu
*Past Negative	ではなかった dewa nakatta		ではありませんでした dewa arimasen deshita
			ではなかったです dewa nakatta desu
Volitional	だろう darou		でしょう deshou
Te-Form	で de		でありまして de arimashite
Conditional	なら/ならば nara/naraba	であれば de areba	–
Attributive	の/な no/na	である de aru	–

De aru and its derivatives are generally used when the writer wants to express that they are explaining something, where as da and desu are used for asserting a fact. You’ll also find uncontracted forms like de areba more frequently in written Japanese.