です (desu) is one of the very first things you learn in Japanese. If you didn’t see it for the first time in a text book, you noticed it in anime, attaching itself to the end of sentences like a period. It’s everywhere. And how could it not be? It’s the foundation of being itself.

In this article, I’m going to take you step-by-step through every single aspect of this word (well, cupola, well, … sigh. We’ll get to it later). How to use it, how to pronounce it, and where it came from, plus a bunch of details in between. Way more than you imagined!

**What does desu mean?**

です (desu) is usually pronounced “des” and is a verb—specifically a copula—placed at (or very near) the end of a sentence to state that something “is,” or “exists.” Basically, “desu” creates a declaration. “Ka” can be added to make it a question.

What’s it like? The easy part

“Desu” is written in kana, the phonetic sorta-alphabet (really a syllabary) used to write parts of Japanese (you read that right—only parts of Japanese are written in Kana. A total of 4—count ‘em, four—different types of writing are used in Japanese).

Most often you’ll see it written in hiragana as です (de-su). Occasionally, you might see it written in katakana as デス. When written in katakana it can mean something different, but we’ll get to that later.

Since it’s written as “desu” you might think you would pronounce it as “deh-soo,” but that’s not the case. For all intents and purposes, it’s pronounced “des” (dehs).

How do you use it? The Harder Part

So, we’re going to have to learn a little English to continue learning Japanese. Unless you’re a grammar nerd (or were a particularly diligent student), you’ve never heard the term “copula.”

The copula has a pretty simple job. It connects a noun to a predicate, aka the verb giving information about the sentence. In Japanese, the desu copula is its own predicate.

In its most simple form, we use desu to create a declaration. “X is Y.” Or, “X is.” This usually comes in the form of XはYです. We can drop the はY part to make the declarative Xです. We can also drop the です and retain the meaning, but the assertive feeling of the statement is dampened.

Let’s try some examples to illustrate:

ペンは青いです。
Pen wa aoi desu.
The pen is blue.

ペンです。
Pen desu.
It’s a pen. (They’re pens.)

青いです。
Aoi desu.
It’s blue.

You may have noticed the parenthetical on the second example. Japanese doesn’t distinguish between “is” and “are.” That’s something to keep in mind going forward.

Time for Tense

Tense in Japanese is a sticky situation. For present and future, you’re going largely on context. For past tense, luckily, we get a nice, simple conjugation.

For the past tense, desu becomes deshita (です→でした). You use it exactly the same way.

There’s another layer to this tense thing, though. To negate a verb, there’s no word you use. In fact, Japanese verbs come with their very own conjugations of each tense to create negation. In this case we get:

ではありません (written, present negation)
dewaarimasen
じゃありません (spoken, present negation)
jaarimasen

ではないです (written, present, stronger negation)
dewanai-desu
じゃないです (spoken, present, stronger negation)
janai-desu

Alright, now we just have to take these and make the negations past tense as well.

ではありませんでした (written, past negation)
dewaarimasen-deshita
じゃありませんでした (spoken, past negation)
jaarimasen-deshita

ではなかったです (written, past, stronger negation)
dewanakatta-desu
じゃなかったです (spoken, past, stronger negation)
janakatta-desu

And all of that? That’s just the polite form.

Down to Earth: the casual (plain) forms of desu

Desu is the polite form of the copula. If we want to bring things down a level to the plain form, we do the following:

です → だ
desu → da

じゃないです → じゃない
janaidesu → janai

でした → だった
deshita → datta

じゃなかったです → じゃなかった
janakatta-desu → janakatta

To make a super-colloquial version of desu, use ssu (です→ っす).

Cranking it up: humble desu and beyond

If you’re talking to the CEO, a customer, or perhaps your s.o.’s parents, you might want to make your speech a little more formal. To do this, we turn desu into a few different things. First, let’s look at how to speak humbly about ourselves:

です → でございます
desu → degozaimasu

ではありません → ではございません
dewaarimasen → dewagozaimasen

でした → でございました
deshita → degozaimashita

ではありませんでした → ではございませんでした
dewaarimasen-deshita → dewagozaimasen-deshita

If you get sent back in time to fuedal Japan and need to go undercover as a samurai, you can always break out “degozaru” (でござる).

If we want to go the other direction and speak “honorifically” about someone else ( e.g. “He is the CEO”), then we use these:

です → でいらっしゃいます
desu → deirasshaimasu

ではありません → でいらっしゃいません
dewaarimasen → deirasshaimasen

でした → でいらっしゃいました
deshita → deirasshaimashita

ではありませんでした → でいらっしゃいませんでした
dewaarimasen-deshita → deirasshaimasen-deshita

Regional Desu

Of course, because this is Japan we’re talking about, nothing’s easy. If you travel to the Kansai region (think Osaka, Kyoto, and Kobe) then desu becomes ya (です→ や). Keep going west and it becomes ja (じゃ). Further south, cha (ちゃ) gets added in. Some areas use all of these, or a few, or… Uh, just ask a local when you arrive.

And if you’re talking to an old person, note that they tend to say ja instead of desu.

Bill & Ted’s Nihongo Adventure

If you get sent back in time to feudal Japan and need to go undercover as a samurai, you can always break out “degozaru” (でござる) instead of desu for the humble form.

Beyond that, in classical Japanese you’ll see niari (にあり), nari (なり), and tari (たり). I’m not going to go into a full breakdown of these because:

A) My grasp of regular Japanese is slippery enough without diving into the wild world of Classical Japanese.

B) Anyone who needs to know these will probably have a big, smart textbook in front of them when they use ‘em.

Where did desu come from?

Ya’ll know I love giving you a good origin story for these words. Unfortunately, the etymology on this one is neither concrete, nor particularly interesting.

Desu seems to have many competing ancestors, namely the contracted forms of either de-sou, de-arimasu, de-aru, de-ohasu, de-gozaimasu, de-suru, or de-sourou. Of those, only the first two seem to have much backing behind them.

Desu first shows up during the Muromachi period (1337-1573), the time immediately before the world-famous Sengoku and Edo periods that feature everyone’s favorite samurai stories. The word is used at the time primarily in Kyogen and Noh plays as a way to declare the entrance of daimyo, high officials, monks, and demons. Later, it was used in daily speech by “ruffians and prostitutes.”

It wasn’t until the end of the Edo period (around the mid-19th century) that the word began to resemble its current usage. After the Meiji period ended, desu began to be used widely.

Changing desu

You’ve probably noticed that desu doesn’t always (or even usually) come alone. There’s typically all these extra sounds tacked to the end. “Ka” (か), “ne” (ね), and “yo” (よ) being the most common you probably hear. So, let’s go through them.

Desuka (ですか) turns the declaration into a question. ”Ka” basically acts like a verbal question mark here.

Desuyo (ですよ) adds emphasis to the declaration. In this case, it’s like an exclamation point.

Desune (ですね) adds something like, “isn’t it?” to the end.

**The other desu**

Remember how I mentioned the two different syllabic writing systems? Well, while desu can be written as either です or デス, most commonly when it’s written as デス it means “death.”

This is a case of Japanese using katakana to Japanify an English loan word. If you think about it, “des” can sound a bit like “death” if the “th” sound isn’t made properly. That’s where it comes from.

This word, as far as I can tell, is only used when writing things that come from English, or to give a sort of English flair.

So, for example, “death metal” is written as “desu-metaru” or デスメタル.

Usually, the idea of “death” is said as “shi” and written as し or 死.

That’s all folks

There you have it, an utterly comprehensive overview of the word “desu.” I hope I cleared up all the possibly mysteries of this deceptively un-simple word.