Traditionally, there are six "base forms" for Japanese verbal words, of which five are still used in modern Japanese. This traditional scheme is called ぶんご文語, literary style, and is associated with Japanese, while the modern scheme is called こうご口語, colloquial style, and is associated with normal modern Japanese. Because it is always a good idea to look at where a language has come from, in order to understand why it does what it does in its current form, the relation between classical and modern Japanese will be mentioned wherever possible.

First, let's look at which base forms are used in classical and modern Japanese:

The way these bases are formed for the two classes of verbs and the verbal adjectives is the major difference between these verbal classes. Verbs in Japanese are mostly regular (there are only a handful of verbs with irregularities), and fall into one of two classes: "godan", ごだん五段, or 'five grade' verbs, and "ichidan", いちだん一段, or 'single grade' verbs. Both verb classes end, in their "dictionary" form, on one of the う—row syllables (although not ず, and consequently づ, and not ふ or ぷ), so that any verb you may encounter can be found in a dictionary to end on う, く, ぐ, す, つ, ぬ, ぶ, む or る (the "dictionary" form mentioned here is a common descriptor used in literature on Japanese, and is synonymous with the れんたいけい連体形 form of verbs or verbal adjectives.

The 五段 verbs (also referred to as "class I", "type I" or "u verb" in literature) can end on any of the aforementioned syllables, but 一段 verbs (also referred to as "class II", "type II" or "ru verbs" in literature) only end on る. Verbal adjectives — the class of adjectives in Japanese that inflect just like regular verbs do — only come in one class and always end on the syllable い, which is why they are also referred to in literature as "i-adjectives" (a second class of adjectives, the adjectival nouns, are commonly referred to as "na-adjectives"). However, while it is useful to know on which syllables verbs and verbal adjectives can end, bear in mind that just because verbs end on う—row syllables and verbal adjectives end on い, not everything ending on an う—row syllable is a verb, and not everything ending on い is a verbal adjective — "all cats have four legs, but not everything with four legs is a cat".

Let us look at how the bases for both verbs and the verbal adjectives are formed. Looking at them as a combination of verbal stem and some final syllable(s), the following table describes each of the bases for these word classes:

In this table, the 命令形 for the 一段 verbs and verbal adjectives are starred, to indicate there's something special about them. First, the 一段 verb 命令形 is a bit of a problem: the word 命令形 can refer to either the grammatical base form, or to the actual verb inflection as it is used in sentences. In classical Japanese, both interpretations of the 命令形 were "stem + よ"; the grammatical base form was the same as the final inflected form. However, in modern Japanese the final inflected form is either "stem + ろ", if you're in an area that adheres to ひょうじゅんご標準語, 'standard Japanese' (the kind spoken in Tokyo), or fairly uniformly "stem + よ", if you're not. This raises the problem that either the 命令形 is listed as two separate forms — something I'm not too fond of — or listing it as just the stem, and then telling you the final inflected forms are either 命令形 + ろ or 命令形 + よ depending on where you are. In this book, I've taken the latter approach.

In addition to this, the verbal adjective 命令形 is a point of contention. In Japanese, verbal adjectives came in two types: く adjectives and し adjectives. Both of these had a regular form, as well as a form involving a contraction with the verb ある, meaning "to be", forming ～かり adjectives. Because of this, the し and く versions were 'pure' adjectives, in that they had no imperfective or commanding form; for adjectives those would make no sense. However, because of ある, the かり variants did have these forms, instead missing a finalising and perfect form. This gave rise to the following rather elaborative set of bases in 文語:

This is a lot of inflectional potential, but as classical Japanese transitioned to modern Japanese, all these forms have essentially become merged, leading to a single inflectional scheme that mixes forms from the 'pure' versions of adjectives with the ある-contracted versions of those adjectives, leading to the question of which forms are to be considered belonging to the adjective as it exists now, and which belong to the the verb ある, which happens to work together with verbal adjectives a lot. In this book, we'll consider the final inflected 命令形 for verbal adjectives to be a contraction of the verbal adjective's 連用形 and the 命令形 for the verb ある, which is あれ. This gives us "verbal adjective stem + く" + "あれ" → "verbal adjective stem + くあれ", where くあ contracts to か, giving us a final rule "stem + かれ". So, in this book, verbal adjectives are considered not to have a genuine 命令形 of their own, instead relying on the helper verb ある for one. However, other books list it as being simply "stem + かれ", and so for completeness it has been included in the earlier table of bases.

Having covered the "what they look like", let's look at what this means for a number of verbs from both classes, and for verbal adjectives:

There are two things worth noting in these tables. Firstly, the 未然形 for 会う is not a typographical error; it really is わ, not あ. This is a left-over from classical Japanese: 五段 verbs ending on う used to be verbs ending on ふ and う (being 'wu', rather than 'u'), which inflected respectively as -は, -ひ, -ふ, -へ, -へ and -わ, -ゐ, -う, -ゑ, -ゑ (ゐ and ゑ being the now obsolete Japanese syllables for 'wi' and 'we', which have not been in use since the written language was reformed in 1946 by cabinet order). However, both were pronounced as -わ, -い, -う, -え and -え. When these two verb classes were simplified to today's 五段 verbs ending on the modern う, the 未然形 pronunciation わ was kept, as well as its written form.

The second thing worth noting in the table is the seemingly disproportionate number of examples for 五段 verbs ending on -る. The reason for this is that for some verbs ending on る, just looking at the verb's dictionary form is not enough to determine whether it's actually a 五段 or an 一段 verb, so a few examples are needed to show how to tell the two apart. If a verb ends on る, and the syllable preceding it in the あ—, う— or お—row (such as is the case for 分かる, 売る and 起こる) then this is always a 五段 verb. However, if the syllable before the る is in the い— or え—row, then it might be an 一段 verb instead. The annoying thing is that without actually looking up the verb in a dictionary, or seeing it used in some inflected form that lets you spot the difference between a 五段 base and an 一段 base being used, there is no way to tell what kind of verb you're dealing with. Luckily, telling the difference when we do have an inflected form is really easy, as we can tell from the following 一段 inflection examples (taking note that the 命令形 as used in this book is just the stem):

Comparing this table with the previous one shows that for any inflection involving the 未然形, 連用形 or 命令形, which cover most verbal inflections, we can readily tell the difference between a 五段 and 一段 verb. The only cases that can leave us uncertain are the 連体形 and 已然形 forms. In these cases, we'll just have to resort to checking a dictionary to be sure of which verb class we're dealing with.

Lastly, a list of examples for the verbal adjectives is quite uniform:

Of course, the examples of verbal adjectives wouldn't be complete without one very curious verbal adjective:

Normally, verbal adjectives end on い, preceded by either an あ—, い—, う— or お—row syllable. However, 執念い is the only verbal adjective in Japanese that ends in an え—row syllable + い. This is in fact so unusual that it is virtually never used, and you will likely not find this adjective in most dictionaries. So, because there's only the one, we can safely state that if you find something that ends in い but it has an え—row syllable preceding it, it is virtually certain not to be a verbal adjective.

Throughout the course of this section we will look at basic inflections for verbs and verbal adjectives, as well as look at a small number of particles that are intricately interwoven with verbal grammar. We shall also look at the basic use and formation of nouns and adverbs, so that this chapter in effect covers the minimal basics of "basic Japanese". We will start by looking at which particles are essential in order to understand basic verb grammar, and will move from there to simple verb forms: present and past tense, as well as affirmative and negative forms. In order to get an overview of the basic concepts involved without offering too much information at once, polite verbal grammar will not be introduced until the next chapter, after basic grammar has been covered.

Particles

Verbal grammar - present tense

Negative

There are three irregular verbs in Japanese that we need to look at before moving on to further inflections, being する, "do"/"decide on", く来る, "come" and ある, "exist" (for inanimate things).

The irregular verb する

The irregular verb 来る

The irregular verb ある

The irregular adjective いい

Past tense

Past negative

In summary, we can draw up tables for verbal inflection, plus the irregularities:

inflecting 五段 verbs

inflecting 行く

inflecting ある

inflecting 一段 verbs, including 来る

inflecting する

inflecting ずる and じる

inflecting verbal adjectives

inflecting いい (よい)

inflecting ない (無い)

There are three important particles that we can use when dealing with noun inflection/declension, being の, と, and や.

The particle の is generally explained as being used to genitivally link nouns, but that doesn't tell us what it really does. In Japanese, genitive is expressed as either marking possession (origin or root concept), description, or a contextualising construction. In English, examples of these would be 'my car' in "this is my car", 'love song' in "this is a love song", and 'old story' in "that's just an old story", but while in English these are seemingly different constructions, in Japanese they all use の:

これはぼく僕のくるま車です。

"This is my car."

In this sentence, which illustrates の being used for possession, the function is fairly obvious: "[X]の[Y]" means "[X]'s [Y]" or "[Y] of [X]". This is the simplest use of の. However, things get more complicated when we look at the other three functions.

これはあい愛のうた歌です。

"This is a love song."

In this sentence, the idea behind the pattern is slightly more complicated, because it's related to a pattern of thought that we're generally not used to in English. In the sentence, the "song", 歌, is considered a specific kind of song, which we can explain by saying "it genitivally stems from 愛", meaning that as a whole, the word derives its core meaning from 歌, but its nuance from 愛. This is a complicated way to look at what's going on in a seemingly simple particle, so it is usually easier to note the specific interpretation instead: we can say that 愛 describes 歌, or that 愛 acts as context for 歌, and that this construction is closely related to the idea of a compound noun.

In this interpretation, "[X]の[Y]" typically translates to "[X] [Y]" in English, so that 愛の歌 becomes "love song", and for instance むかし昔のはなし話 becomes "old story" (with 昔 being a noun meaning 'long ago', and 話 meaning 'story'). If we use this in a slightly bigger, more interesting sentence, we see the following:

ただのむかし昔のはなし話です。

"(That)'s just an old story."

This sentence is particularly interesting because it uses の twice. ただの[X] means "just X", with ただ meaning 'just' or 'merely', and [X] being any noun phrase, in this case "昔の話". This kind of chaining can be taken to extremes, such as in the following example:

うちのねえ姉さんのともだち友達の「ささき佐崎」があそ遊びにき来た。

"My sister's friend, Sasaki, came over (today)."

Let us analyse what happens in this chain. It usually makes most sense to analyse long chains like these by looking at the [X]の[Y] patterns in a last-to-first order, because (as always) the most important words come last:

While this sounds like an artificial example, it is actually quite common to find three or even four nouns linked through の to create a single, more and more specific noun phrase. The main issue with learning to use these patterns, and more importantly, understanding them while listening to native speakers, is that the most important information comes last, so you have to keep track of all the context nouns before the final operative noun gets used.

The other two particles, と and や, are much simpler to understand than の: と links nouns to form an exhaustive list, while や forms a representative list. For instance, if someone went to the supermarket and bought orange juice, milk and tea, and that's all they bought, then we can list all these things with と:

ジュースとぎゅうにゅう牛乳とおちゃ茶をか買った。

"(I) bought juice, milk and tea."

However, if they instead bought a lot of refreshments (say they were planning a party), then the following sentence would be easier than listing every individual item on the shopping list:

ジュースや牛乳やお茶を買った。

"(I) bought juice, milk, tea (and the like)."

That's the only difference between と and や (for the purpose of noun listing). Both form a list of items, and by using と you imply that what you describe is the whole list, while if you use や you imply that even though it's a list, it's not the whole list, just a representative snippet. Of course, it (almost) goes without saying that you cannot mix と and や.

Actual inflection of nouns relies on copula verbs, as it does in English. While in English only the verb "to be" fulfils the role of copula, in Japanese there are a number of copulae to pick from. So, for the moment, we will look at the two most common copulae: the plain form だ and its polite counterpart, です. Technically, these are both verbs, although だ is somewhat more complex than です. If we look at their verb bases, we see the following:

First, there is no 命令形, which kind of makes sense — one cannot order something to all of a sudden have some property; chairs don't become red because you order them to, people don't become angry just because you tell them to, and it doesn't suddenly become night because you ordain it so. At least not without superpowers of some sort, which are beyond the scope of this book.

Secondly, the "copula" column is a bit special: it tells you which form is typically used when a certain base form is relied on. When we need a 連体形 copula, we can use either だ or です depending on whether we want plain form or polite form, but when we need a continuative (which will be explained in the next chapter), modern Japanese uses で.

Third, there is a 終止形 entry, which most modern verbs do not use. The reason it exists for (this) copula is that だ is relatively special: when used to end noun phrases, its 終止形 is used, and so it uses the form だ. However, when used attributively (effectively turning nouns into adjectives), which uses the 連体形, the classical 連体形 is used and we end up with な. Although the language reforms of the 20th century have for the most part merged the functions of 終止形 and 連体形, this particular instance of separate form has been preserved, rather than gotten rid of. Luckily you will rarely, if ever, need to recite the bases for です or だ, but だ is used attributively so frequently that you should have little problem remembering when to use だ and when to use な.

Present tense

Past tense

Negative

Past negative

In summary

Before you can say something "is" something else, it first has to "become" this something else. In Japanese, the process of becoming is expressed with the verb なる, which can be used to describe particular state (such as "becoming cold") through the use of state nouns or adjective-derived adverbs, as well as being usable to describe particular thing (such as "becoming an adult") by using it with nouns. Finally it can of course also be used to describe the process of "becoming" itself, (such as "to quickly become [...]") by using proper adverbs.

The verb なる is a 五段 verb, without any irregularities, meaning its bases are なら, なり, なる, なれ and なれ.

While typically used in combination with the verb particle に, it can also be used in combination with the particle と (not in its role as noun lister), in which case its meaning changes from "become" to "be" (often interpreted as the immediate future "will be"). This can be illustrated with some に/と comparison sentences:

ちから力になります。

"(This) will become (our) strength".

力となります。

"(This) will be (our) strength".

バンドのしゅつえん出演はごがつ五月にじゅうよっか二十四日になります。

"The band's performance will be set to (literally: become) May the 24th."

バンドの出演は五月二十四日となります。

"The band's performance will be on May the 24th."

We already looked at です and だ, but we haven't really looked at how they fit together with other existential verbs, and how each differs from the other.

Where in English the verb "to be" is used as both a copula (the verb that sets up definitions such as "A is B") and as a existential verb (the verb that indicates existence somewhere, such as "A is [here]"), in Japanese these are two (or more accurately, three) distinct roles. To indicate that "A is B", distinct copulae are used in Japanese. These include だ, です, but also several less frequently used copulae such as である, でござる and でいらっしゃる.

The existential verb role, on the other hand, is actually performed by two distinct verbs in Japanese: one describing existence for animate objects (such as humans, animals, and things that can be considered animate, like "AIBO" robot puppies and the like) and one describing existence for inanimate objects and abstract things. These are いる (居る) and ある (有る), respectively. To illustrate the difference between animate and inanimate, let's look at two sentences:

いぬ犬がいる。

"(There) is a dog."

ほん本がある。

"(There) is a book."

In both sentences, が marks the preceding part as subject of the sentence. Both sentences translate to "there is X", but in the first sentence X is a dog, which is an animate 'object', and because of this, we need to use いる. In the second sentence X is a book, which is rather inanimate, and thus ある is used. Also, in both sentences, the word "there" is entirely implied. Because we are using verbs to mark existence and we are talking about actual instances of dogs and books, saying they exist means we also say they exist at some location.

If we only want to define something, i.e. say something "is" a thing, such as "it is a dog" or "it is a book", we use a copula instead. For most people used to western language, these verbs may at first glance seem to do the same as what いる and ある do; after all, the sentence "it is a dog" is essentially the same as the sentence "there is a dog" with the word "there" replaced with "it". However, there is a very important difference: in "there is a dog", we are saying that a dog exists somewhere, whereas in "it is a dog", we are defining some "it" to be of the category "dog".

Put concisely, definitions in Japanese can only be done using copulae, and marking existence can only be done using いる or ある:

犬です。

"It is a dog."

本だ。

"It is a book."

本がしかく四角です。

"Books are rectangular."

犬がどうぶつ動物だ。

"Dogs are animals."

We've already seen する as irregular verb, and it has been used in enough example sentences to let it be no surprise that it means "do". However, this isn't the only meaning for this verb. When used in combination with a direct object — as transitive verb — する does mean "do", but when used as intransitive verb, its meaning should be considered to be "decide on" or "choose". To show this difference in meaning between the transitive (strictly speaking, たどうし他動詞) and intransitive (strictly speaking, じどうし自動詞) versions of する, two short sentences:

なに何をするか。

"What are (you) doing?"

何にするか。

"What will (you) pick?"

In the first sentence, を marks the preceding as direct object to the verb, while in the second sentence, に marks the preceding part as indirect object to the verb. The difference in meaning is striking.

There is a third meaning to する, when paired with the particle と, which is "to consider something ...":

これがわたし私がひつよう必要とするものです。

"These are the things (that) I consider important."

We're not quite done treating ある; while it means "exist" for inanimate things, this meaning also leads it to be usable for what in English is represented by "to have" in sentences like "I have a radio". In Japanese, you don't say you "have" something, but that "something is with you". For instance, if I want to say that aside from my portable radio I also have a radio at home, instead of saying "I have a radio at home too" I would say "there is a radio at my house too":

うちもラジオがある。

"(I) have a radio at home, too."

Because of this double role, it's quite an important verb.

I know that ない is not a verb, but the reason it's in this list is because of ある, which is very much a verb. Since ある means "exist" for inanimate things, and since the adjective ない means "not (exist)", there are actually (almost) always two interpretations possible when ない is used in a sentence, by virtue of ある having two possible interpretations:

ラジオがない。

1) "(There) is no radio."

2) "(I) do not have a radio."

So for this reason it has been included in the list of important verbs; if we look at it as the negative form for ある, which we should, then it's a verb form, and a very important one at that.