History of だ

And what it has in common with じゃない。

If we want to understand how the だ came to be, we have to back in time to the auxiliary verb にあり which came to be from particle に expressing localization and あり (modern ある) indicating existence.

Eventually, にあり was then shortened to なり. And for example with certain nouns, it was used to indicate a state in which they are, which gave birth to なり adjectives, and later modern な adjectives among others.

But in general, main use of なり was to assert that A is B (A=B). “to be”. This is called copular use, and なり is also called copular particle. Copula is a link between subject and predicate – like “to be” in English.


A thing of beauty is a joy forever. The 美しき is a noun modifying form of adjective. In modern language we would use 美しい.

未然形(imperfective form (things that not happened), nai stem) (みぜんけい)なら
連用形(conjunctive form (connects), masu stem)(れんようけい)なり・に
終止形(predicative form, ending form)(しゅうしけい)なり
連体形(attributive form, noun modifying form)(れんたいけい)なる
已然形(realis form (thing that happened, used with ば and ども as in けれども)(いぜんけい)なれ
命令形(imperative form) used for orders (めいれいけい)なれ

Notice that なり has alternative conjunctive form に.

As we learned in previous article, in classical Japanese, てwas added to conjunctive form of the verb. Let’s look at the て attached to なり conjunctive form.

連用形(conjunctive form)にて

Eventually, this にて changed to で.

(there was also particle にて used back then in casual language indicating location where some action takes place, means of doing something or cause which also changed to で , particle we know and some even like)

This で (which we can call the て form of なり) was itself followed by the auxiliary verb あり. Which in turn gave birth to the であり and modern である.


Between XIV and XVI centuries, the であり form changed to だ in Kanto area and ぢゃ(じゃ)in Kyoto area and the なり conjugations became obsolete.

This is also reason why the では is replaced with じゃ for example in じゃない and why だ pronunciation can vary in different areas of Japan (for example you can see videos of some older Japanese reading kana ‘だ’ as ‘じゃ’.


Some of you are probably curious about the etymology of です, the most famous Japanese words, which is polite equivalent of だ.

And to be honest the history of です is shrouded in mystery.

But one of possible etymologies is contraction of であります, でございます、でおわす or でそうろう (the last two are classical honorific verbs).

Next week I will try to cover the origin of polite conjugations 🙂

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