Ichidan Verbs　一段活用動詞

Ichidan Verbs　一段活用動詞

Japanese verb classes differ in how they conjugate. More specifically, what defines a verb’s class is its bases. Endings themselves do not necessarily change based on verb class.

In this lesson, we will look at the ichidan verb class, commonly also known as “ru-verbs” given how all these verbs end in /ru/ in their basic form. This class constitutes roughly half of all verbs. 

Before we get into new content, let’s recap important terminology. 

• Verb: A word that describes an action, state, or occurrence. It may constitute the predicate at the end of a sentence or be part of a noun-predicate when used as a participle/modifier. 
• Predicate: The part of a sentence that makes a statement about the subject. 
• Intransitive Verb: A verb that only takes a subject and does not take an object. Abbreviated in definitions as “intr.” 
• Transitive Verb: A verb that takes both a subject and an object. Abbreviated in definitions as “trans.”
• Auxiliary: An ending that helps construct verbal conjugations.
• Object: A noun that is directed by the main verb of the sentence.
• Direct Object: A word that receives the action of the main verb of the sentence.
• Case Particle: A particle that denotes a particular grammatical function/case.
• Base: One of the six forms that a verb may take which is then followed by endings (auxiliaries, etc.). 
• Terminal/Predicative Form: Known in Japanese as the 終止形, it marks the end of a complete sentence/the predicate. 
• Attributive Form: Known in Japanese as the 連体形, it is used to make a verb, adjective, etc. into a modifier that goes directly before a noun. 
• Basic Form: The basic form of any given phrase. It is utilized in plain speech and in many grammatical circumstances. The basic form encompasses both the predicative and the attributive forms in the context of verbs and adjectives. 
• Continuative Form: Known in Japanese as the 連用形, it is used with endings pertaining to actions being carried out.

The Basic/Non-Past Form
一段活用動詞の基本形・非過去形

The plain¹ non-past form requires no conjugation for verbs, but it does correspond to two conjugational bases: the predicative form (終止形) and the attributive form (連体形). While these forms are identical for Ichidan verbs, they refer to separate ways to use a verb. Collectively, they are referred to as the basic form (基本形). 

Meaning	Basic Form	Meaning	Basic Form
To see	見る	To borrow	借りる
To wear	着る	To remember	覚える
①To get up ②To happen	起きる	To exist (animate objects)	いる
To eat	食べる	To open (trans.)	開ける
To answer	答える	To close (door, etc.)	閉める

Whereas adjectives require context to be interpreted in the future tense, verbs are more likely to be interpreted either way (plain or future) in the non-past form. Furthermore, there are no morphological distinctions between the “present tense,” the “future tense,” and the “infinitive form².” The infinitive form in English refers to the base form of a verb, and it is used in the chart above to define the Japanese verbs—marked by the use of “to.” This is often referred to as the “dictionary form” (辞書形) from a practical standpoint.

Various factors such as readily perceivable contexts, most likely topics (if not present already), or even the nature of the verb itself may result in some, all, or only one reasonable interpretation on the grounds of tense or whether the statement is just like the English indicative form.

1. 映画を見る。
i. (I) watch movies.
ii. (I) will watch (a) movie(s).
iii. To watch movies.

2. 浴衣を着る。
To wear a yukata.

3. 毎朝起きる。
i. (I) get up every morning.
ii. To get up every morning.

4. 鳥がいる。
There is a bird.

5. 毎日野菜を食べる。
i. To eat vegetables every day.
ii. (I) eat vegetables every day.

Exs. 1-5 are examples of the “predicative form” because the verb is the predicate, and it is at the end of the sentence. Meanwhile, Ex. 6 is an example of a verb being used in its attributive form, as the verb is before a noun to modify its meaning.

6. 食べる野菜 
Vegetables that (I/one) eat(s)/will eat

The Polite Non-Past Form w/ ～ます　
非過去の丁寧形 （～ます） 

Conjugating verbs into polite speech involves the auxiliary verb ～ます. One way or another, it finds itself in every conjugation in all formal (polite, respectful, humble) speech registers. With the introduction of this ending, we must learn the verb base it attaches to as well as what bases of  ～ます we need to make other conjugations in polite speech. 

～ます attaches to the “continuative form” (連用形). As ～ます in its basic form is understood to be non-past, it fits this base’s definition of being matched with endings pertaining to actions being carried out. To form this base with Ichidan verbs, all you do is drop the final ～る, then you just add ～ます. 

Meaning	Basic Form	Continuative Form	＋-～ます
To think	考える	Kangaeru → Kangae	考えます
To fall (intr.)	落ちる	Ochiru → Ochi	落ちます
To close up/shut	閉じる	Tojiru → Toji	閉じます
To lose	負ける	Makeru → Make	負けます
To show	見せる	Miseru → Mise	見せます

7. ドアを閉じます。
I’ll close the door.

8. ちょっと考えます。
I’ll think about it.

9. 教科書を借ります。
I’ll borrow the textbook. 

Basic Form: Predicative vs. Attributive w/ ～ます
非過去形「～ます」の終止形・連体形との使い分け

Previously, we learned how です does not possess an attributive form, which prevents copular, adjectival, and adjectival-noun polite forms from directly modifying nouns. Although verbs use the auxiliary ～ます to become polite, it does, incidentally, have both a predicative form (終止形) and an attributive form (連体形). However, its attributive form is rarely used because of a convention found in Modern Standard Japanese grammar dictating that politeness need only be marked at the end of a sentence. This results in Ex. 10b being ungrammatical to the majority of speakers.

10a. よく借りる教科書　〇
10b. よく借ります教科書　X/△
Textbook(s) that I often borrow 

～ます only appears before nouns in extremely formal speech, and said nouns are almost always dummy nouns which serve grammatical functions as opposed to referring to a specific entity. At this point in your studies, it is more than safe to assume that “～ます + noun” ought to be treated as a grammatical error.

The Plain Past Form w/ ～た　　
常体語における過去形（～た）

To conjugate Ichidan verbs into the past tense in plain speech, all you do is conjugate it into its continuative form (連用形) by dropping the final ～る and add the auxiliary verb ～た, which we learned already marks the past tense for other parts of speech. 

Meaning	Basic Form	Continuative Form	+ –ta た
To find (trans.)	見つける	Mitsukeru → Mitsuke	見つけた
To collect	集める	Atsumeru → Atsume	集めた
To get used to	慣れる	Nareru → Nare	慣れた
To collapse	倒れる	Taoreru → Taore	倒れた

Grammar Note: Because the predicative form (終止形) and attributive form (連体形) of the auxiliary verb ～た are identical, past tense clauses can directly modify any noun phrase. 

11. あの絵を見た。
I saw that picture/painting.

12. さっきあの店で見た絵はすごかったです。
The painting/picture I saw earlier at that shop was amazing.

13. 切手を集めた。
I collected stamps.

14. クマを見つけた。
I found the bear. 

15. だいぶ慣れた。
I’ve gotten fairly used to it. 

Grammar Note: Perfect tenses such as the perfect past used here in the English translation – “have gotten used to” – do not exist in Japanese, and so both “past tense” and “perfect past tense” fall under the use of ～た in Japanese.

The Polite Past Form w/ ～ました
丁寧語における過去形（～ました）

The continuative form of ～ます (まし～) is combined with ～た to create ～ました, the polite past form of verbs. From this process, the concept of Japanese conjugation behaving like a chain becomes clear. Take a verb, put it into whatever base is needed, attach an ending, and continue attaching endings as needed. 

Ex. Miru (to see) → Miru → Mi– → Mimasu → Mimashi– → Mimashita (saw).

Below are more examples of verbs conjugated with ～ました. 

Meaning	Basic Form → Continuative Form	+ ～ました
To get	得る → E-	得ました
To increase (intr.)	増える → Fue-	増えました
To plant	植える → Ue-	植えました
To mix (trans.)	混ぜる → Maze-	混ぜました
To line up (trans.)	並べる → Narabe-	並べました

Grammar Note: Although the auxiliary verb ～た possesses a fully functional attributive form (連体形), because of the tendency to only mark politeness once at the end of the sentence, ～ました is rarely used directly before nouns. In typical everyday polite speech, this is considered a grammatical error.

16. 木を植えました。
I planted a tree.

17. 肩を並べました。
We lined up shoulders.

18. 人口が増えました。
The population increased/grew.

19. 調味料を混ぜました。
I mixed in spices. 

20a. 混ぜた調味料　〇
20b. 混ぜました調味料 X
Spice(s) that I mixed  

The Plain Negative Form w/ ～ない
常体語における否定形（～ない）

To make the negative form in plain speech for verbs, you must conjugate the verb into a base known as the irrealis form (未然形) and follow it with the auxiliary ～ない. The irrealis form (未然形) is used to indicate actions/events that have not occurred yet, and so the negative form is a perfect application of this.

To form the irrealis base (未然形) with Ichidan verbs, all you have to do is drop the final ～る This is identical to the continuative form (連用形), but this WILL NOT be the case with all the other verb classes. 

Meaning	Basic Form → Irrealis Form	＋ ～ない
To break (intr.)	壊れる → Koware-	壊れない
To bathe in	浴びる → Abi-	浴びない
To get wet	濡れる → Nure-	濡れない
To get off	降りる → Ori-	降りない
To seem/appear	見える → Mie-	見えない

Grammar Note: Because the auxiliary adjective ～ない conjugates as an adjective, its predicative form (終止形) and attributive form (連体形) are fully functional. 

Grammar Note: To remember how the attributive form (連体形) functions with verbal phrases, whether it is of the negative form or some other conjugation, is that it plays the role of “who/what/where/when” when following a noun to mark the start of the modifier. This is not so obvious because of how the Japanese word order is opposite.

21. 引き戸が壊れない。
The sliding door won’t break.

22. シャワーを浴びない。
To not/will not take a shower.

23. 負けない。
I/we won’t lose.

24. 足が濡れないよ。
(Your) feet won’t get wet. 

25. シャワーを浴びない子は意外と多い。
There are surprisingly a lot of kids who don’t shower.

The Polite Negative Forms
(～ません or ～ないです)　
丁寧語における否定形（～ません・ないです）

There are two possible negative forms in polite speech. The difference in politeness between the two is that Method 1 is deemed politer and more formal. 

• Method 1: Attach the politeness marking auxiliary ～ます to the continuative form (連用形) of the verb, then attach the auxiliary verb ～ん³ to the irrealis form (未然形) of ～ます: ませ～ ＋ ～ん.
• Method 2: Attach the negative marking auxiliary ～ない to the irrealis form (未然形) of the verb, then attach the politeness marking auxiliary⁴ ～です to the terminal/predicative form (終止形) of ～ない (ない～).

Method 1: ～ません (Proper Polite Form)

Meaning	Basic Form → Continuative Form	＋～ません
To change (trans.)	変える → Kae-	変えません
To admit/recognize	認める → Mitome-	認めません
To investigate	調べる → Shirabe-	調べません
To sleep	寝る → Ne-	寝ません
To attach	付ける → Tsuke-	付けません

Method 2: ～ないです (Casual Polite Form)

Meaning	Basic Form → Irrealis Form	＋ ～ないです
To clear up/be sunny	晴れる → Hare–	晴れないです
To be popular	モテる → Mote-	モテないです
To leak	漏れる → More-	漏れないです
To feel	感じる → Kanji-	感じないです
To swell	腫れる → Hare-	腫れないです

Grammar Notes:
①Although ～ません does possess an attributive form (連体形), its use is incredibly rare in modern speech. As such, for practical purposes, its placement before generic nominal phrases is considered ungrammatical.
②As for ～ないです, its use before nouns is impossible because ～です does not have an attributive form (連体形).  

26. 今夜寝ません。
I won’t sleep tonight.

27. 何も感じません。
I don’t feel anything.

28. （お）肉は食べません。
I don’t/won’t eat meat.

29. 神を信じません。
I don’t believe in God/gods. 

30. 内容は漏れないです。
(The) content won’t leak.

31. 魚は食べないです。
I don’t eat fish. 

The Plain Negative Past Form w/ ～なかった
常体語における過去の否定形（～なかった）

To create the negative past form in plain speech, the auxiliary ～ない must be conjugated into its past tense form. Connecting ～ない to the verb itself is no different than as with the non-past tense, attaching to the irrealis form (未然形). 

To conjugate ～ない into the past tense, first use its continuative form (なかっ～) and attach the past tense marker ～た: ～なかった.

Meaning	Basic Form → Irrealis Form	＋～なかった
To disappear	消える → Kie–	消えなかった
To forget	忘れる → Wasure–	忘れなかった
To throw away	捨てる → Sute–	捨てなかった
To exceed	超える → Koe–	超えなかった
To believe	信じる → Shinji–	信じなかった

32. 消えなかった証拠
Evidence that didn’t disappear

33. 彼はごみを捨てなかった。
He didn’t throw away the trash.

34. 忘れなかったよ。
I didn’t forget.

The Polite Negative Past Forms (～ませんでした or ～なかったです)
丁寧語における過去の否定形（～ませんでした・なかったです）

The polite negative forms for Ichidan verbs are created in very familiar ways. In fact, you already learned them already when we learned how to conjugate the copular verbs. The only difference is learning how to conjugate the start of the conjugation chain with Ichidan verbs! As was the case with marking non-past negation, there are two methods to mark past tense negation in polite speech. 

• Method 1: Attach the politeness marking auxiliary ～ます to the continuative form (連用形) of the verb, then attach the auxiliary verb ～ん to the irrealis form (未然形) of ～ます (ませ～). Then, attach ～でした to the attributive form (連体形) of ～ん (ん～).
• Method 2: Attach the negative marking auxiliary ～ない to the irrealis form (未然形) of the verb, then attach the past tense marking auxiliary ～た to the continuative form (連用形) of ～ない (なかり⁵～). Then, attach です to the terminal/predicative form (終止形) of ～た (た～). 

Method 1: ～ませんでした (Proper Polite Form)

Meaning	Basic Form → Continuative Form	＋ ～ませんでした
To begin/start (trans.)	始める → Hajime-	始めませんでした
To leave/exit	出る →  De-	出ませんでした
To finish (trans.)	終える → Oe-	終えませんでした
To throw	投げる → Nage-	投げませんでした
To lower (trans.)	下げる → Sage-	下げませんでした

Method 2: ～なかったです (Casual Polite Form)

Meaning	Basic Form → Irrealis Form	＋ ～なかったです
To run away	逃げる → Nige–	逃げなかったです
To hurt (trans.)	傷つける → Kizutsuke–	傷つけなかったです
To carry forward (trans.)	進める → Susume–	進めなかったです
To compile	纏める → Matome–	纏めなかったです
To cool down (intr.)	冷める → Same–	冷めなかったです

Grammar Note: The negative-past polite forms do not directly modify nouns because no form of です–including でした–possesses an attributive form (連体形).

35. 話題を変えませんでしたよ。
I didn’t change the topic. 

36. ピザを食べませんでした。
I didn’t eat pizza. 

37. なかなか焦げませんでした。
It wouldn’t quite get charred.

38. 特に調べませんでした。
I didn’t particularly check/investigate it.

39a.  食べなかったピザ 〇
39b. 食べませんでしたピザ X
The pizza I didn’t eat 

40. 今日は晴れなかったです。
It didn’t clear up today. 

41. コイは逃げなかったです。
The koi fish didn’t swim away. 

42. お風呂はなかなか冷めなかったです。
The bath didn’t quite cool down. 

1. “Plain” refers to “plain speech,” which is the opposite of “polite speech.” Polite speech is always marked somehow in verbal constructions. Thus, the “plain (non-marked) form” of a verb may be referred to as its 普通形, and the “polite (marked) form” of a verb may be referred to as its 丁寧形. ↩︎
2. The “infinitive form” is the base form of a verb, and it is the English equivalent to the concept of the 基本形, although the latter’s grammatical capacity is far larger than the former. ↩︎
3. The original negative auxiliary verb in Japanese is ～ず, which itself is believed to be a combination of the continuative form of the negative marking morpheme /n/ and the verb す (to do). When the terminal/predicative form and the attributive form of most parts of speech merged together, this merger also affected ～ず, becoming rendered as ～ぬ before contracting to ～ん. ↩︎
4. The politeness marking auxiliary verb ～です should not be confused for when です is used as the polite copula verb. ↩︎
5. As we learned in Lesson 14, when ～た follows the かり-continuative form (連用形), the base becomes contracted. So, for ～ない, this means its continuative base なかり becomes なかっ. ↩︎