Introduction to Japanese: Volume 1

Chapter 10

Plain form verbs

Last chapter, we learned about how to form and use adverbs, as well as some basic information about onomatopoeia in Japanese. In this chapter, though, we will retrace our steps further, studying verb conjugation. This time we will learn about the plain form of the verbs, rather than the polite ones we have seen so far.

What is the “plain form” of a verb?

The plain form of a verb, also called the dictionary form (since it is the one you will find in dictionaries) or basic form, is the informal present affirmative form of the verb. The verbs we have seen so far – 食べます, 飲みます, 行きます, きます, etc. – are the formal present affirmative form of the verb. As I mentioned, we started with the polite form because for new speakers, it is always smart to err on the side of politeness rather than informality, and also because they are easier to learn due to their regularity.

Having said that, the plain form is arguably the one Japanese speakers use the most in their daily interactions, given that it is used with family and friends. As “polite” as the polite form is, once you start getting intimate with your friends, continuously using the polite form may make you sound “みずくさい”, that is, distant, reserved, or even stand-offish.

Furthermore, just like we can make adverbs from adjectives, in Japanese we can form other verb conjugations from the plain form, such as the so-called “te form” or “participle”. Therefore, in this chapter we will also learn about the overall structure and grammar concerning Japanese verbs. This might be a bit hard and even a bit dry (although we will do our best to come across as simple and intuitive), but will be helpful for the entirety of your Japanese studies.

The plain copula: だ

When we started our studies of Japanese, one of the first things we saw was the copula (that is, a word used to link a subject to a predicate) です. While not properly a verb, we learned how to use and how to conjugate its polite form. The plain form of です is だ, and it is used pretty much in the same way as です is.

私は学生です (formal) //   私は学生だ  (informal)

Similarly, there are plain form equivalents for the present negative, past affirmative and past negative tenses: ではない, だった and ではなかった, respectively. The table below conveys all the information in an easier to see way.

Polite form Plain form
Affirmative です でした だった
Negative ではありません ではありませんでした ではない ではなかった
Present Past Present Past


Plain form verbs

Just like all Japanese verbs in the polite form end in -ます, all plain form verbs end in –u. By –u, I mean a Hiragana character such as う, く, つ, る, etc. Checking some verbs we already know, for example, the plain form of 食べます is 食べ, while the plain form of 飲みます is 飲, of 行きます is 行 and of はなします is はな.

English Meaning Polite form Plain form
To drink 飲みます 飲む
To go 行きます 行く
To talk はなします はなす
To say いいます いう
To enter はいります はいる
To eat 食べます 食べる
To see 見ます 見る
To forget わすれます わすれる
To come きます くる
To do します する


The three Japanese verb groups

How can I conjugate plain form verbs? How can I convert the polite form into the plain form, and vice-versa? To answer these questions, we must learn about the three types of Japanese verbs.

Japanese verbs are divided according to the way they are conjugated. So far this distinction has not been of relevance for us, since in their polite form, all Japanese verbs are conjugated the same (hence them being easier to learn), but now that we will learn the plain form, it is worth knowing the three groups.

Group 1 – also called godan (“five steps”) – verbs are the most common type of verb. They are called five-steps because they suffer changes according to the verb conjugation. The first five verbs of the list above are all godan verbs (how convenient!).

Notice that when we convert them from the polite form to the plain form, they lose the -ます part and then we change whichever -i Hiragana they had to -u.

In easier to understand terms:

Polite Form Verb Stem Plain Form
飲みます → 飲みます 飲み 飲む
行きます → 行きます 行き 行く
はなします → はなします はなし はなす
いいます → いいます いい いう
はいります → はいります はいり はいる


Easy, right?

Group 2 is composed of the ichidan (“one step”) verbs. They are the second most common type of verb in Japanese. They are called “one step” because they do not suffer the changes that the godan ones do. Note that in their case, we simply remove the ます part and append る to obtain the plain form.

Polite Form Verb Stem Plain Form
食べます → 食べます 食べ 食べる
見ます → 見ます 見る
わすれます → わすれます わすれ わすれる


Group 3, finally, is comprised of only two verbs: きます (to come) and しますto do する – conveniently for us, the last two verbs of our list! We call them irregular verbs. Because they are the only verbs in this group, it is often said that Japanese only has two irregular verbs, which is not entirely correct.

I would rather say that きます and します are the only highly irregular verbs in Japanese, in the sense that none of their conjugations follow the standard patterns. This is because there are other verbs that are mostly regular but have one or more irregular conjugation.

Polite Form Plain Form
します → します する
きます → きます くる


Plain form conjugation

Now that we know how about the three Japanese verb groups, we can proceed to their verb conjugation. As we did with the polite form, we will learn the present affirmative, present negative, past affirmative and past negative conjugations. The plain form conjugation is somewhat more difficult than the polite form, though.

This time, we will do things a bit out of order. Let’s start by the Group 2 conjugation, since I believe it to be the easiest one. Learning it will also make learning the other ones easier.

First, remove the る (or the ます, if you are conjugating them from the polite form) part of the verb, then add ない for the present negative, た for the past affirmative, and なかった for the past negative.

In easier terms:

Present affirmative Present negative Past affirmative Past negative
食べる 食べない 食べた 食べなかった
見る 見ない 見た 見なかった
わすれる わすれない わすれた わすれなかった
でる でない でた でなかった
いる いない いた いなかった


These conjugations look somewhat similar, right? They might remind you of the i-keiyoushi (adjective) conjugation, especially the negative ones. This is why I asked you to bear this in mind when we talked about adjectives two chapters ago.

Before tackling Group 1, let us quickly check the Group 3 conjugation, since it only has two verbs anyway. As always, you are better off just memorizing these two verbs. Also note that while the first Hiragana character changes, the conjugation themselves are the same as Group 2.

Present affirmative Present negative Past affirmative Past negative
する しない した しなかった
くる こない きた こなかった


The Group 1 conjugation is the hardest one by far. The reason is that not only does it differ from the other two groups, but the conjugations also differ among themselves depending on the ending of the verb (that is to say, the conjugation for verbs that end in う is slightly different than the one that ends in く).

Having said that, there are patterns (やった!). When we conjugate them in the negative tense, we need to change their –u Hiragana into –a, then add ない for the negative present tense, or なかった for the negative past tense like we have done so far with all other verbs.

Come again? Don’t worry, this is easier to understand when shown. Take the verb 行きます. We already know that its plain form is 行く. To conjugate it into the negative present tense, we need to change its last Hiragana く into か, then add ない: 行かない. With the verb 飲みます, we get its plain form 飲む, change the む into ま and add ない, getting the final conjugation 飲まない.

As for the past affirmative tense, this one changes according to the ending of the verb, so let’s see how we conjugate them one by one.

Group 1 conjugation – う verbs
Present affirmative Present negative Past affirmative Past negative
かう かわない かった かわなかった
いう いわない いった いわなかった


The first thing we have to notice here is that for verbs that end in う, like かう (to buy), いう (to say) or あう (to meet), when we conjugate the verb in the negative, we substitute the う for わ, never for あ. When using the past affirmative tense, we substitute the う for った. This pattern will reappear in other verb groups too.

Remember, by the way, that when speaking Japanese paying heed to this pause is vital for you to be understood. Without the pause, いった (“said”) becomes いた (“was”).

Group 1 conjugation – く verbs
Present affirmative Present negative Past affirmative Past negative
かく かかない かいた かかなかった
きく きかない きいた きかなかった
行く 行かない 行った* 行かなかった


For the く verbs, such as かく (to write) and きく (to listen, to ask), the past affirmative is done by substituting the く for いた. This is the only verb group where this happens. Also, please note and memorize that 行く(to go) has an irregular past affirmative conjugation, as we write 行った, not 行いた. This, by the way, is why I said that there are verbs that are mostly regular but have one or more irregular conjugations.

Group 1 conjugation – ぐ verbs
Present affirmative Present negative Past affirmative Past negative
およぐ およがない およいだ およがなかった
いそぐ いそがない いそいだ いそがなかった


The ぐ verbs conjugation is very similar to the くones, such as およぐ (to swim) and いそぐ (to hurry). In a certain way, you are just repeating the く conjugation but adding the 〃mark, substituting the ぐ for いだ. This is also the only verb group where this happens.

Group 1 conjugation – す verbs
Present affirmative Present negative Past affirmative Past negative
はなす はなさない はなした はなさなかった
けす けさない けした けさなかった


I have always thought the す verbs conjugation, like はなす (to talk) けす (to erase), to be easier, as the past affirmative conjugation is identical to the する verb.

Group 1 conjugation – つ verbs
Present affirmative Present negative Past affirmative Past negative
かつ かたない かった かたなかった
まつ またない まった またなかった
もつ もたない もった もたなかった


Sometimes we may forget that the つ (tsu) sound belongs to the T-group of verbs, so when we conjugate them in the negative tense, please remember to exchange them for た. Also, please note that when using the past affirmative tense with the つ verbs, like かつ (to win), まつ (to wait) and もつ (to carry), we substitute the つ for った just like we do with う verbs.

Group 1 conjugation – ぬ verb*
Present affirmative Present negative Past affirmative Past negative
しぬ しなない しんだ しななかった


The verb しぬ (to die) is the only verb in Japanese that ends in ぬ. Its past affirmative tense, when we substitute ぬ for んだ, will be repeated in the next two verb groups.

Group 1 conjugation – ぶ verbs
Present affirmative Present negative Past affirmative Past negative
よぶ よばない よんだ よばなかった
あそぶ あそばない あそんだ あそばなかった


One of them is the ぶ verbs, like よぶ (to call) and あそぶ (to play, to have fun)…

Group 1 conjugation – む verbs
Present affirmative Present negative Past affirmative Past negative
飲む 飲まない 飲んだ 飲まなかった
よむ よまない よんだ よまなかった


… and the other are the む verbs, like 飲む (to drink) and よむ (to read).

Group 1 conjugation – る verbs
Present affirmative Present negative Past affirmative Past negative
はいる はいらない はいった はいらなかった
つくる つくらない つくった つくらなかった
ある ない あった なかった


Finally, the る verbs, like はいる (to enter) and つくる (to make, to produce). Like the う verbs and the つ verbs before them, in the past affirmative we substitute る for った.

Another exception, though, is the very basic verb ある (“to be” or “to exist” for inanimate objects), whose negative forms are simply ない and なかった. In a certain way, when you conjugate a verb or adjective in the negative tense, what you are doing is appending this ない – this “is not” or “does not exist” – to the original verb.

The second thing we need to talk about verbs that end in る is how to identify which of them belong to Group 1 (はいる, つくる, ある) and which belong to Group 2 (食べる, 見る, でる), and regarding that, I have some bad news. Most verbs that end in –eru, like 食べる and でる, belong to Group 2, but there are a few exceptions, like かえる (to return), which belongs to Group 1.

There is also no clear pattern regarding verbs that end in -iru; to make my point clear, look no further than いる (“to be” for animate),which belongs to group 2, and いる (“to need”), which belongs to group 1. In short, simply by looking at a verb that ends in るthere is unfortunately no way to know whether it belongs to Group 1 or 2.

Before we finish our chapter, let me give you one last table (I promise!) just to wrap-up the Group 1 conjugations regarding the past affirmative tense:

Group 1 conjugation – Past affirmative
If the plain form verb ends in..

…replace it with… った かう→ かった
まつ → まった
ある → あった
いた かく → かいた
いだ およぐ → およいだ
した はなす → はなした

んだ しぬ → しんだ
あそぶ→ あそんだ
よむ→ よんだ


Phew! Today’s chapter was probably hard, and I am sorry for that. However, knowledge of the plain form is crucial to any serious learner of Japanese, as not only it is the most commonly used form in daily interactions, grammatically it also has other functions other than indicating informality. But that will be the topic of another article.

Shukudai section

Rewrite the dialogues below, converting the polite form to plain form.


Doudou: Midori, what did you do yesterday?
Midori: I did not do anything yesterday! I rested the entire day at home. And you?
Doudou: I studied yesterday. After that, I talked with Tanaka-sensei.


Hiroki: Tomorrow we will have a party! Kayoko, did you buy food?
Kayoko: Ah! I went to the market, but I did not buy food.
Hiroki: Really? Why?
Kayoko: I forgot.
Hiroki: Well, I will buy food then.


Because of our heavy emphasis on grammar in this chapter, we will learn only 5 Kanji this time. Four of the Kanji below are used in some of the verbs we saw in this chapter, while one of them is a simple enough Kanji that is often used in combination with some of the Kanji we have seen so far.

This Kanji means “to enter” or “to insert”; the first verb is はいる (to enter) and the second one れる. Another reading you will often see is 入り口 or 入口いりぐち (entrance).

The Chinese reading of this Kanji is にゅう, appearing in words such as 入学にゅうがく (entering a school, enrolment), 入国にゅうこく (entering a country) and 輸入ゆにゅう (importation). I always found it convenient to remember this reading to think that a student who has just entered a school is a new student, which is exactly how the word sounds in Japanese: 入学生にゅうがくせい (new student).

Finally, one word about this Kanji’s writing. Because of the similitude between 入 and 人 (person), there is one convention that we must follow. For 人 (person), the first, leftmost stroke is the longest one, with the right one starting from it. For 入 (enter) we do the opposite: first we do a smaller first stroke from midway, then we do the longer stroke.

Sample sentence: ヒロキは入学生にゅうがくせいだ. (Hiroki is a new student.)

Sample sentence: スーパーの入口いりぐちはあそこです. (The supermarket’s entrance is over there.)

This Kanji means “to exit, to come out”, or “to get out, to reveal”. The first verbs correspond to the Japanese word る and the later ones to す, so take care with their reading.

The word “exit” (as opposed to entrance) is 出口でぐち. The Chinese reading is しゅつ, such as in the word 輸出ゆしゅつ (export).

Interestingly, this Kanji also carries the connotation of appearance, like in English “come out and play”. Examples are the words 出演しゅつえん (performance, stage appearance) and 出席しゅっせき (attendance).

Sample sentence: 田中先生たなかせんせいました. (Tanaka-sensei left.)

This very easy to write Kanji means “mouth”, “opening” or even “gate”. Please note that it has no relation whatsoever to a square; the Japanese is reading is くち, appearing in words such as くち (mouth), 一口ひとくち (mouthful, morsel), 口紅くちべに (lipstick), 辛口からくち (dry as in wine) and 甘口あかくち (sweet as in wine).

When a single door is used as both entrance and exit, by the way, we have a 出入口でいりぐち. Finally, the Chinese reading is こう, most notably appearing in 人口じんこう (population).

Sample sentence: かよこは辛口からくちワインがすきですが、みどりは甘口あまくちきです. (Kayoko likes dry wine, but Midori likes sweet ones.)

This Kanji means “to say”, appearing in the verb う (to say). I have always looked at this Kanji looking at sound waves leaving from the 口 below; feel free to use this metaphor if it helps you. The Japanese reading of this word is also used words such as かた (way of talking) and わけ (excuse).

The Chinese reading is げん, appearing in many words, such as 言語げんご (language), 宣言せんげん (proclamation), 方言ほうげん (dialect) and 予言よげん (prediction).

Another Chinese reading that is less common but as equally important is こと, appearing in a word as basic as 言葉ことば (word).

Sample sentence: ヒロキのかたはとてもかわいい (Hiroki’s way of speaking is cute.)

This Kanji means “to talk”. Before delving further into its reading, I think that this character is a good example of how initially scary or complex Kanji can get progressively easier as you learn their components. For example, the entire left part of this Kanji is 言, which makes it easier to write and already hints about this character’s meaning.

Back to the main topic. “To talk” in Japanese is はなす. The Chinese reading わ is used in words such as 電話でんわ (telephone), 話題わだい (topic), 会話かいわ (conversation) and 神話しんわ (myth).

Sample sentence: 田中先生たなかせんせい電話でんわはなした. (I spoke with Tanaka-sensei on the phone.)