Japanese Verbs and Conjugation

This is an introduction to Japanese verbs and conjugation, and provides the background for Part 2 of the Beginning Lessons. This lesson doesn't require you to have read anything else in Part 1, but the rest of Part 2 assumes that you are familiar with most of Part 1.

Recommended background:

The Structure of a Japanese Sentence

Where We're At

If you've been reading from the beginning, you should have a pretty good understanding of the basic structure of a Japanese sentence:

[Topic] [Subject] [Adjuncts] [Objects] [Verb/Adjective] [Sentence-ending particles/
clausal conjunction]

As you've seen, only the verb or adjective is strictly necessary. Other elements are often omitted for brevity, or simply not needed in every sentence. Though we've shied away from the details of verbs and adjuncts so far, most of this was pretty straightforward – put the right things in the right spots and you're all set.

Now we get into the tricky stuff, because there's not much we can do with verbs until we talk about verbal arguments and conjugation.

What is a Verb?

The traditional definition for a verb is something that expresses an "event" or "state of being". While this may be true, it's not a terribly helpful definition since most adjectives are arguably "states" and there are plenty of nouns that represent "events". So once again, let's step away from the meaning of verbs and instead focus on how they are used.

But first, we need to set one thing straight: the "verbs" that you would find in a Japanese dictionary are actually made up of two parts: the verb itself, and tense.

Take the verb taberu, for example. Normally translated as "to eat", taberu is not a root word, but a verb with a present tense suffix, which you can easily see by comparing it with the past tense form.

Hiragana Romaji Gloss Translation
たべる tabe-ru eat-PRES (I/you/someone) eat(s)
たべた tabe-ta eat-PAST (I/you/someone) ate

So it's really just tabe that means "eat". While English verbs appear in their bare, untensed form in dictionaries, verbs in Japanese dictionaries appear in dictionary form, which is simple present tense. We'll use dictionary form most of the time when talking about individual verbs, but we need to make the distinction between verb roots and tensed verbs if we're going to make sense of Japanese verb conjugation.

By this point you may be asking, "Is this really any different from English?" After all, if we ignore irregular past forms like "ate", plenty of English verbs show present and past tense suffixes, "learn-s" and "learn-ed" for example. Although the difference isn't clear when you look at simple verbs, Japanese and English start to diverge when we add in auxiliary verbs.

But before we get into any of that stuff, let's finish what we started in the previous lessons by filling in some details about verb arguments and case particles.

Arguments and Case Particles

In The Structure of a Japanese Sentence you learned about the case particles ga and o, which mark subjects and objects respectively. Every Japanese verb takes a subject, and some also take objects. Verbs that take an object are called transitive verbs, and those that don't are intransitive.

Some verbs take two objects; these are called ditransitive verbs. In English, some verbs that allow both of these objects to be nouns, but usually one or both appear as part of a prepositional phrase. In Japanese, all nominal objects are marked by case particles; when there are two, one is marked by o, and the other by a different particle, ni.

Verb Type Arguments Example English
Intransitive Subject [Yamada-san ga] hashiru. Yamada runs.
Transitive Subject and object [Matsutani-san ga] [raamen o] taberu. Matsutani eats ramen.
Ditransitive Subject and two objects [Shindo-san ga] [Suzuki-san ni] [meishi o] ageta. Shindo gave (his) business card to Suzuki.

In the case when there are two objects, the ni object goes first by default, but object ordering is one of the places where Japanese is particularly flexible. The key thing to remember is that the particle determines the thematic role (the meaning) of the object, not the position.

As it turns out, objects that are nouns in English tend to be o objects in Japanese, and to-phrases in English are usually ni objects in Japanese. These categories also line up with accusative and dative case-marked nouns in other languages.

However, some object that are nouns in English take ni in Japanese, some prepositional objects in English use o in Japanese. Furthermore, just as it's possible for English verbs to take just a single prepositional object, some Japanese verbs take only a ni-object.

  English Japanese
Noun Phrase <-> Ni-object Bill boarded/rode [the train]. Biru-san ga [densha ni] notta.
Prep. Phrase <-> O-object Mary looked [at an old picture]. Mearii-san ga [furui shashin o] mita.

In addition to o and ni, there are several other particles that frequently mark objects in Japanese, including kara (from), made (to), and to (with), which have more of an inherent meaning associated with them. These are not considered to be case particles, but normal postpositions, just like prepositions in English.

Finally, entire clauses can also be objects, such as in "John said [that Ana went shopping]” and “Fred asked [if the movie was any good]". Japanese has such embedded clauses too, but we have to put them off until we get to the necessary conjugations.

Now we turn our attention to the more difficult aspects of verbs: auxilary verbs and verb conjugation.

Inflections, Auxiliaries, and Tense

Inflection, roughly, is a change in a root form of a word that has a purely grammatical basis. Inflection commonly takes the form of affixes, that is, prefixes and suffixes.

One form of inflection is agreement, where verbs and adjectives change form to match the characteristics of the nouns they are associated with, such as person (I/you/he), number (singular vs plural), and gender (he vs she). Japanese verbs do not agree with thieir subjects for person, so there is no differerence between "I/you eat" and "he/she eats" in Japanese. There is no agreement for number or gender either, unlike most European languages.

But Japanese verbs do have a variety of grammatical suffixes. In addition to tense suffixes, which you've already seen, there are also the auxiliary verbs, often shortened to just auxiliaries, which are words that appear in addition to a main verb and modify its basic meaning.

Does it sound a bit odd to you that suffixes can be words? The truth is that what counts as a "word" is not always clear, but one trait of words is that they have unique positions in a sentence, and in this respect, Japanese auxiliaries are exactly like English auxiliaries. Let's look at one Japanese auxiliary with a close English equivalent: the passive auxiliary.

Hiragana Romaji Gloss Translation
たべられる tabe-rare-ru eat-PASSIVE-PRES (something) is eaten
たべられた tabe-rare-ta eat-PASSIVE-PAST (something) was eaten

There's a difference here that's easy to overlook at first glance, but we can tease it out if we make a gloss for the English version as well.

Japanese English
tabe-rare-ru is eat-en

Note: "past participle" is a term borrowed from Latin grammar and has nothing to do with past tense in English.

There, now we can see it: the English passive construction is made up of two components, the auxiliary "be" and the verb suffix "-en", but in Japanese there is just a single passive auxiliary.

Furthermore, in the English version, the tense suffix was attached to the main verb in the simple case, but now it's attached to the auxiliary. Effectively, the tense suffix has moved. In the Japanese version, there's something much simpler going on: the relative ordering of the verb and tense is unchanged, and the passive auxiliary –rare is just inserted between them.

Although the difference is subtle, verbal suffixes actually fall into two categories:

  • The first, like -ed and -en in English don't have a unique sentence position, but instead latch onto other verbal elements depending what combination those elements appear in. -ed appears on whatever verb or auxiliary is first, and -en appears on one that is preceded by be.
  • The other, like -ru and -ta in Japanese, do have a unique sentence position, much like what we normally think of as a "word", and not really any different from auxiliary verbs in Japanese, or English for that matter. In Japanese, the verb is always first, tense is last, and auxiliaries come in between.

So the "verb" slot in our sentence structure from above is actually made up of at least three slots. Actually, let's add in negation (also a "suffix" in Japanese) too, to make the pattern even more clear.

Piza wa tabe- -rare- -nakat- -ta.
  [main verb] [auxiliary] [negation] [tense]

English has the "tense" position as well, but only future tense (will) makes use of this position in simple sentences. The entire sequence is exactly the same as in Japanese, just mirrored.

The pizza will not be eaten.
  [tense] [negation] [auxiliary] [main verb]

Really, this should come as no surprise when you consider that the noun-preposition and verb-object orderings in these two languages also mirror eachother.

What's interesting about English is that we can put a variety of other words with more complex meanings, like "can", "might", and "should", in the tense position as well. Such words are called modal auxiliaries, and share the characteristic of implying that the event in question may not have actually happened yet.

Japanese, on the other hand, doesn't have any auxiliaries of this exact sort, or even a distinct future tense. What I've been calling "present tense" is really non-past tense, and is distinguished between present and future by context or with adjuncts such as "now", "at 3:00", "next week", and so on.

Verb Classes

As I alluded to in the beginning, verb conjugation in Japanese isn't quite as simple as tacking on all the desired suffixes, though this does account for a great deal of it. As you saw, Japanese lacks the complex gender/person/number agreement on verbs found in European languages as well as the general weirdness of English irregular verbs.

But Japanese verbs and auxiliaries do vary in form slightly depending on what combination you use them in. Let's look at a few forms of another verb, "to write", with dictionary form kaku.

Hiragana Romaji Gloss Meaning
かかれる kak-are-ru write-PASSIVE-PRES (something) is written
かきます kak-imas-u write-POLITE-PRES (someone) writes
かく kak-u write-PRES (someone) writes
かける kak-e-ru write-POTENTIAL-PRES (someone) can write

Note: normally you wouldn't use this weird hyphenation for the Romaji, but at the moment we're interested in what exactly each part is.

From this we can clearly see that the root of kaku is kak. You should also notice that the present tense suffix is -u rather than -ru – more on this in a bit.

Verbs like kaku which have a stem that ends in a consonsant are called consonant-stem verbs, and the other type, like taberu, are called vowel-stem verbs. ("Root" and "stem" mean the same thing in the current context.)

The significance to this distinction is that it lines up exactly with the two regular conjugation classes in Japanese – every consonant-stem verb is in conjugation Group I, and every vowel-stem verb is in Group II. There are almost no verbs that don't fall into one of the two conjugation schemes, and within each group, all verbs conjugate alike, with almost no exceptions.

With that, I'll go ahead and give you your first conjugation rule: the present tense suffix takes the form –u for Group I verbs, and –ru for Group II verbs.

Most auxiliaries also fall into these categories. In other words, the form of a second auxiliary (including tense markers) depends on the first as if it too is in either Group I or II. For example, –rare is in Group II, so the present tense marker is –ru if it directly follows.

What are the exceptions then? The main verbs suru (to do) and kuru (to come), and the auxiliary verb mas(u) (the politeness marker). But even suru and kuru look like Group II verbs in most of their forms (with some quirks), and mas(u) behaves mostly like a Group I verb (hence the 'u' that usually follows). There are also a handful of verbs that are irregular in a single form (iku, aru, kureru, iu).

Finally, there are a number of verbs that are made by combining a noun with suru – we call these suru verbs. For example, kaimono is "shopping", and kaimono suru is "to shop". The suru in these verbs conjugates the same way as the lone suru.

How to Tell Which Conjugation Class a Verb is In

From what you know so far, you should be able to give me a verb in dictionary form if I give you the root. But what if you need to go in the other direction? Since any verb you find in a dictionary is going to be in, well, dictionary form, this is information you need in order to conjugate it.

Identifying Group I verbs is easy: if there's no 'r' directly preceding the final 'u', then it must be in Group I. We know this because the present tense suffix for Group II verbs is always -ru. Group II verbs are trickier, since a verb ending in 'ru' could have a root that ends in 'r', or the 'r' might be part of the present tense suffix.

Fortunately, there are no Group II verbs ending in "-aru", "-uru", or "-oru", so such verbs are guaranteed to be in Group I. But for verbs ending in "-iru" or "-eru", you will need to memorize which group each is in. There are even a few pairs of Group I and II verbs that look the same in dictionary form, such as kaer-u (to go home) and kae-ru (to change).

There are also some verbs that appear not to have any consonant before the final 'u', such as kau (to buy), yet conjugate as Group I verbs. All such verbs actually have a silent 'w' in their root, which shows up in the passive form, such as in kaw-are-ru. Remember that 'wa' is the only remaining 'w' mora in modern Japanese, and that words that used to have 'w' before any other vowel are now pronounced with just the vowel.

In summary, for verbs in dictionary form:

  • If there is a consonant other than 'r' before the final 'u', the verb is in Group I.
  • If there is no consonant before the final 'u', the verb is in Group I.
  • If the verb ends in -aru, -uru, or -oru, it's in Group I.
  • If the verb ends in -iru or -eru, it may be in Group I or II.


As we noticed above, the present tense marker has the form -u after Group I verbs, like in kak-u and kak-imas-u, and -ru after Group II verbs, like in tabe-ru and tabe-rare-ru. For this reason, Group I verbs are also called u-verbs and Group II verbs are also known as ru-verbs.

Curiously, the disappearance of the 'r' in present tense u-verbs happens to prevent two consonants from occurring in sequence (there's nothing like "kak-ru"). Similarly, the extra 'i' in kak-imas-u is absent in tabe-mas-u, the polite form of taberu, avoiding two adjacent vowels (no "tabe-imas-u").

As it turns out, this rule is remarkably consistent: if adding an auxiliary would cause there to be two consonants or vowels in a row, the second consonant or vowel is deleted. In other words, what we're seeing here is contraction. This pattern actually accounts for the majority of the differences between Groups I and II.

The Conjugation Process

At this point, I can finally give you a decent definition of "conjugation". One traditional definition is something like "the inflection of verbs", but as you've seen, verb conjugation in Japanese involves affixation (suffixation, to be specific) and contraction, but not inflection of the sort found in European languages. Let's make this our definition instead:

Japanese verb conjugation = affixation + contraction

Additionally, there are a couple situations where other sound changes are required. One is in irregular verbs such as suru and kuru, and the other is in auxiliaries beginning with 't', which cause sound changes in the preceding verb or auxiliary if it is in Group I (yes, it really is that specific).

To review, here's the full process:

  1. Start with a root verb.
  2. Choose the first auxiliary to add as a suffix.
  3. Choose the correct form of the auxiliary depending on the conjugation class of the root.
  4. If applicable, change the form of the root to fit with the chosen auxiliary (usually not necessary).
  5. Repeat steps (2-4) for any additional auxiliaries.

The good news is that you already understand the basic principle behind step 3, leaving less to memorize than would otherwise be necessary. And in the case of step 4, all the relavent auxiliaries (those starting with 't') cause exactly the same sound changes, so there is only one pattern to memorize.

What Next?

From here we'll move into the practical side of using verbs, inclusing your first two conjugated verb forms, masu-form and te-form and their derivatives, as well as a some basic particles and a few special groups of verbs.

Continue on to:

Masu Form and its Conjugations

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