Japanese conjugation, from two perspectives

August 20, 2020

Learning a language is different when learned as a native language or as a foreign language. We will illustrate this by taking a look at how Japanese as a foreign language (JFL) learners and Japanese as a native language (JNL) speakers learn about Japanese grammar.

Until recently I wasn’t even aware that most JFL text books leave out some interesting things about Japanese grammar. At the same time, these interesting things are commonly taught in Japanese school, but in a different context.

On the other hand, it’s hard to argue with the fact that some sensible simplification used when teaching Japanese as a foreign language will allow students to grasp the fundamental concepts of a language more quickly.

Most Japanese students won’t learn about modern grammar in school. Instead, they will usually learn about Middle Japanese grammar, also called classical grammar, or 古典文法 (kotenbunpō). And Japanese school will spend little or no time mentioning that Middle Japanese exists at all.

Both grammars (Middle and Modern Japanese) are different in a lot of ways. Both grammars are connected by the thread of time, and thus finding new aspects in one of the two will always be refreshing. And surely, it will fend off the feeling of stagnating in the quest for language mastery.

This time, we will focus on verb conjugation. At the end of this article, I hope I can convince you that knowing a little of both can be quite rewarding.

The trouble with conjugation

Verb conjugation is different from language to language, and can sometimes be the bane of a language learner, myself included. Conjugation is a vital part of almost every language’s grammar so it is important to learn it well.

For example, irregular verbs in the English language have to be learned as a triple consisting of the present, past, and past participle form. There are roughly 200 irregular verbs, such as dream/dreamed/dreamt. Most of these verbs are commonly used. To an aspiring language learner this makes learning the language a frustrating experience. Often, there is nothing left than to bite the bullet and memorize everything.

Conjugation is messy.

German, a heavily inflecting language, with a reputation for precision and rigor isn’t any better. Yes, once you know sehen/sah/gesehen, you’re closer to the goal, but now you need to know how to procure singular and plural, and third person plural, and then in passive, and Konjunktiv II (usually called subjunctive), and so on.

And for the record, I only vaguely know how to deliberately use the Konjunktiv II in German, despite it being my native language.

Many more languages have their complicated edge cases and irregular conjugations, so there is a lot of fun to be had conjugating verbs.

I’ve noticed something interesting about how JFL learners learn grammar, and how JNL speakers experience learn the grammar of their own language. One of those differences is how conjugation is taught.

Japanese Conjugation Classes

Japanese like many other languages has the concept of so called verb classes. In Japanese grammar parlance, these are called N-dan. N here is the class number and can be a 1, 2, 4, or 5. And since we are counting in Japanese, we would say ichidan, nidan, yodan, and godan.

While a third verb class is also thinkable, sandan is not commonly described and I couldn’t find any reliable resources on it. Therefore, we choose to remain on the planet of grammatical reality, not possibility, and stick to four possible verb classes. These verb classes can have some minor variations, called upper and lower, as you will see later.

To know why there are 4 verb classes and how they relate to the rest of Japanese grammar, the systematization of syllables and their vowels gives us an answer.

The so called Gojūon table has exactly five rows (five dan), when read from top to bottom, and produces all possible Japanese kana. The five rows correspond to each vowel used in Modern Japanese, a, i, u, e and o. N-dan then will simply indicate how many of those vowels will be used when conjugating a specific verb. But more on that later.

Other W- R- Y- M- H- N- T- S- K- $$\emptyset$$ Vowel
ん (n) わ (wa) ら (ra) や (ya) ま (ma) は (ha) な (na) た (ta) さ (sa) か (ka) あ (a) a
ゐ (wi) り (ri) み (mi) ひ (hi) に (ni) ち (chi) し (shi) き (ki) い (i) i
る (ru) ゆ (yu) む (mu) ふ (fu) ぬ (nu) つ (tsu) す (su) く (ku) う (u) u
ゑ (we) れ (re) め (me) へ (he) ね (ne) て (te) せ (se) け (ke) え (e) e
を (wo) ろ (ro) よ (yo) も (mo) ほ (ho) の (no) と (to) そ (so) こ (ko) お (o) o

: Gojūon table (with Hiragana and Rōmaji)

How I learned Japanese Conjugation

So both JFL learners and JNL speakers learn about matching gojūon dans to verb classes. For JFL, it’s one of the countless grammar books on Modern Japanese, and for JNL speakers it’s their 国語(kokugo) class in school, in which Middle Japanese is covered. So already, we have a hunch that those two target audiences might be received different information.

Of course, as a diligent student of Japanese grammar, I have previously tried my best to memorize my dans. The way it was taught to me was:

There are exactly two verb classes. 一段 (ichidan) and 五段 (godan) conjugation. And some する(suru) and くる(kuru) edge cases.

Simple enough, right? Sure beats learning Russian conjugation. In my history as a JFL learner, all I’ve ever been taught is exactly this fundamental fact: “Japanese has ichidan and godan verbs”.

Ichidan verbs are all those, that end on a “ru”, and godan are those that do not. Let’s, for a second, ignore the fact that some godan verbs end on a る but are conjugated like ichidan verbs.

Sometimes, ichidan verbs are also called consonant-stem verbs, and godan verbs are called vowel-stem verbs. There is no limit how creatively teachers seem to name Japanese verb conjugation, and in the wild, one might also encounter group I/II verbs. Either way you call it, verb classes are being treated as an a or b binary concept.

I want to illustrate the difference in conjugation between the two classes by providing a conjugation table for two simple verbs, 食べる (taberu, to eat) and 書く (kaku, to write), ichidan and godan respectively. We conjugate without looking at the meaning of each individual form in the Japanese language, therefore only observing syntax, not semantics. We provide the 6 conjugation cases

which seem to be the usual way to describe verb conjugations.

食べる (taberu) 書く (kaku) Godan Vowel
Irrealis 食べ (tabe) 書か (kaka) / 書こ (kako) あ / お
Adverbial 食べ (tabe) 書き (kaki) / 書い (kai)
Conclusive 食べ (tabe) 書く (kaku)
Attributive 食べ (tabe) 書け (kake)
Conditional 食べ (tabe) 書け (kake)
Imperative 食べ (tabe) 書こ (kake)

: Conjugation of 食べる (taberu, ichidan) and 書く (kaku, godan)

Ichidan verb conjugation, like with 食べる, is extremely straightforward.

  1. Identify the stem of the verb: 食べる(taberu) -> 食べ(tabe)
  2. Depending on the desired form (negative, infinitive, etc.), append the corresponding particle ending. For example, in order to make the ます (masu) form, Simply append ます and you have 食べます.

You will see that the stem of taberu – tabe – is never touched. It stays the same for all forms. That’s why it’s called ichidan. Simple enough, and easy to learn.

Let’s look at godan verbs, like 書く, now and describe their conjugation:

  1. Identify the stem of the verb: 書く (kaku) -> kak.
  2. Depending on the desired form (irrealis, adverbial, etc.), append the correspond combination of consonant the stem ends on and godan vowel required for this form (refer to table). For example, irrealis would become 書け.
  3. Now append, any necessary particle endings. For example, to receive the ます (masu) form, take the adverbial form 書き and append ます.

And then my eyes opened and I reached nirvana because I finally realized:

It’s called godan because it uses all five dan from the gojūon (duh!). And can you believe that I passed the JLPT N1 (humblebrag) without knowing this at all?

As a matter of fact, the impetus for me writing this article was that I was caught red-handed stammering about ichidan and godan conjugation and not having any clue of what I was talking about.

So one more time, when we look at the kana that start with a k-, or か行, we see five: か, き, く, け, こ (ka, ki, ku, ke, ko). And when we look at all the forms of 書く (kaku), we see that all five happy little kanas are in the house supporting us in the journey of writing this article, with the irrealis doing double duty and housing あ and お.

On our way to passing JLPT N Minus 1 in one fell swoop!

The thing with language education

How do JNL speakers experience their own language? You can gather some first hand data by asking about ichidan and godan conjugation, and in many cases not getting a satisfactory answer.

Do not assume ignorance here. Knowing about a language, and knowing a language are two different things. Once you master your dans, you won’t catch yourself thinking about how to conjugate this or that verb while you’re having a pleasant conversion with someone.

I do not believe that the goal of language education is to speak like a native speaker. First of all, the goal itself by definition is incredibly hard to attain or unattainable. Language is diverse, and language is alive. What might sound native in one part, might sound foreign in another part.

Japanese despite what some might think, has a lot of diversity across this long, vaguely banana (not really tho) shaped country with its lovely disputed islands. And then there are many places like Yonaguni, where the rest of the world conveniently forgets that inhabitants there speak separate, and endangered languages, not dialects of Japanese.

The history of the Japanese language dates back quite a while, possible more than 2000 years. For a language to be trapped on the same island for a long time makes it easy for some individuals to believe or portray that this particular language moves in a linear fashion.

Japanese is described with there being such as things as “Old Japanese”, “Middle Japanese”, and “Modern Japanese”. What is called Modern Japanese right now could move into so many directions, and if you are learning Japanese as a foreign language you are part of that future direction.

And my message to you is, no matter what language you want to master, achieve fluency and proficiency, and then spice it up with who you are! If you bring some English accent into your pronunciation, wear it with pride, because it makes you you.

Total language assimilation is for the Borg (TM) and other cybernetic organisms. Ignore all those superfluous whispers about this or that person and their accent or their mannerisms. Not to mention that in my humble experience this is mostly coming from monolingual persons.

How Conjugation is taught in Japan

Let’s get to another concept though that I would really like to mention here. Because for a long time I just assumed that Japanese would be largely uneducated about Japanese grammar, kind of like I always nod along when my German speaking friends speak about Konjunktiv II and how it’s used when and I have no idea what all that means. Yes, I admit my ignorance.

If we just leave it at that, we are missing out on the good stuff though. So gather along, grammar enthusiasts, and witness the glory of Middle Japanese grammar, the grammatical parental unit of Modern Japanese.

Middle Japanese grammar is a beast of a different make and model, and while you can clearly see how Middle and Modern Japanese are related, it requires significant effort to really understand it. It turns out that many JNL speakers learn about their own language in the context of a school subject called 国語 (kokugo). Kokugo involves deciphering old Japanese texts that were written more than 500 years ago, and understanding where the language comes from.

Not many schools in other parts of the world teach their students much about, let’s say Old German, or Old Norse. But on the other hand I was taught Latin and Ancient Greek in secondary school. The idea there being the same: Knowing about the languages that gave birth to thoughts and ideas that can in turn be found in what you are speaking right now, will help you understand where you are in this world. And you will also learn a lot about grammar.

So far I’ve not come along many Japanese that longingly look back at their days of studying kokugo, but most certainly everyone recalls having to memorize verb conjugation. Learning grammar in Japan as a subject is is usually called 古典文法 (kotenbunpō, classical grammar).

As our subject, we pick Late Middle Japanese (LMJ). LMJ was spoken roughly from the 12th century to the 16th century. The beginning of LMJ is marked by the end of the aristocratic Heian period and it ends around the time Portuguese missionaries made their way to Japan and started describing grammar and phonology. This is also the point where パン (pan) made its way into Japanese. Good to know for all fans of Anpanman.

Famous texts written in LMJ include:

We will now dive into LMJ conjugation and look at some examples.

Remember how modern Japanese is taught as having two classes of conjugation, ichidan and godan? We will start by listing all 9 classes of conjugation in LMJ. These are the classes that are taught in kokugo class in the Japanese school system.

To gain a better understanding, we will first take a look at the superficial differences between what we’ve learned so far on Modern Japanese conjugation and LMJ conjugation.

You will notice that in the first five classes from the list above, we are using 一段 (ichidan), 二段 (nidan) and 四段 (yodan). From this we can deduce that the first five conjugation classes use either one, two or four classes from the gojūon.

Furthermore, we notice the introduction of a 上 (kami) or 下 (shimo), meaning upper and lower respectively. In principle, upper in this context describes a conjugation class that uses い (i) paired with a set of either one or two vowels. In turn, lower describes a conjugation class that uses え (e) paired with a set of one or two vowels. Upper equals i, lower equals e. Easy.

Then, LMJ conjugation has four irregular conjugation classes, that are each named after a consonant: k, s, n and r. These conjugation classes contain words such as

Modern Japanese verbs has less irregular conjugation, but these verbs are still around in some form or another. 来る (kuru) and 死ぬ (shinu), for example, continue existing as they are, with their conjugation being mostly the same (as will be shown below).

Others have been turned into suru verbs, such as 愛す (aisu) and 為 (su). These are nowadays expressed as 愛する (aisuru) and 為る (suru), with the latter usually being written with kana alone, so simply する. suru verbs are usually taught as their own class of verbs in JFL education, and are trivial to conjugate.

As a general rule and as languages go, rarely anything is ever “thrown away”, neither vocabulary nor grammar. Things change slowly and words might fall out of fashion, but when we think about fundamental verbs of a language, we can safely expect them to not disappear that easily. Even 侍り (haberi) is still here, despite being rarely used. In Modern Japanese it is written as 侍る (haberu), with the kana spelling being more frequent.

We will now go back to our regular conjugation classes, and roughly show how they are made up.

As opposed to godan, yodan conjugates using only four vowels out of the gojūon table. The four vowels are a, i, u, and e. To illustrate this with a verb, we will choose our trusty 書く (kaku) again.

書く (kaku) Yodan Vowel
Irrealis 書か (kaka)
Adverbial 書き (kaki)
Conclusive 書く (kaku)
Attributive 書く (kaku)
Realis 書け (kake)
Imperative 書け (kake)

: LMJ Conjugation of 書く

Note how the realis (已然形) in LMJ has become the conditional (仮定形)in Modern Japanese. Yodan is a four-vowel conjugation, and you can see that the “missing” vowel is in the irrealis, where LMJ only has the a ending, but not the o ending.

The last conjugation I want to show is upper and lower bigrade conjugation (上二段活用 and 下二段活用). As the names suggests, they each use 2 vowels out of the gojūon table. Upper indicates that we use i, and u, and if we are conjugating in the lower bigrade conjugation (下二段活用) instead, we use e and u instead. That makes sense, right? The vowels e and u are located lower down the gojūon table.

A word belonging to the upper bigrade conjugation class is 起く (oku, to wake up), which is the old form of 起きる (okiru).

起く (kaku) Nidan Vowel
Irrealis 起き (oki)
Adverbial 起き (oki)
Conclusive 起く (oku)
Attributive 起くる (okuru)
Realis 起くれ (okure)
Imperative 起き (oki)

: LMJ Conjugation of 起く

And to give the classical response to our conjugation of 食べる (taberu) before, we will present the lower bigrade conjugation of 食ぶ(tabu), the LMJ word for 食べる. As mentioned before, the lower bigrade conjugation uses the vowels e and u.

食ぶ (kaku) Nidan Vowel
Irrealis 食べ (tabe)
Adverbial 食べ (tabe)
Conclusive 食ぶ (tabu)
Attributive 食ぶる (taburu)
Realis 食ぶれ (tabure)
Imperative 食べよ (tabeyo)

: LMJ Conjugation of 起く

Here, we see that the u part of the conjugation remains unchanged, when compared to the upper bigrade conjugation, and we are only changing the e parts. Interestingly, the imperative receives an extra syllable, よ (yo).


To know more about the present, learn about the past. That applies to learning grammar. If you know where something comes from, it becomes easier to understand why it looks and behaves the way it does right now.

It would be interesting to show using real examples how these verbs are used in context and I want to illustrate this using excerpts from classical literature in a future post.

PS: Did you know that you can output a word count of the current document in VIM using g CTRL-G? Blew my mind.


Sites that were incredibly useful with my research were


As a side note, when researching this topic, the least helpful was the Japanese Wikipedia on Japanese grammar, since it used some questionable phrasings on the exact nature of who is learning the grammar:

外国人を対象にした日本語教育においては下一段活用とともに「グループ 2」と呼ばれる。

Which translates to

Japanese language education targeted at foreigners calls it together with lower monograde conjugation “Group 2”.

To which I have to say:

  1. None of the text books I have used ever mentioned Group 2 and usually say ichidan, godan, suru/kuru.
  2. Couldn’t the author just have written Japanese as a Foreign Language (日本語教育) literature commonly refers to it as “Group 2”?
  3. What if you are learning Japanese as your second language, while being a Japanese citizen? Does that make you a foreigner?

Maybe it’s just an innocent phrase that accidentally found its way into a Wikipedia article (and basically every other article about conjugation grades, I haven’t gotten around to correcting all of them). And no one was bothered by it for the decade or so it was written there. But Japanese Wikipedia could sure use a dose of “This article only describes the situation in Japan, please find more examples from other countries”.

Using Japanese Wikipedia for research made me realize that as opposed to the English Wikipedia, the Japanese Wikipedia is a monoculture. When a collection of knowledge is written by those belonging to the hegemony of a country, it ends up being one-sided and neither representing the views and opinions of minorities, nor outsiders. With great power comes great responsibility. On the bright side, more and more people learn Japanese, so maybe this can change!

I would be thrilled to hear from you! Please share your thoughts and ideas with me via email.

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