第17課: Ichidan Verbs 一段活用動詞
Japanese has a handful of verb classes which differ in how they conjugate. More specifically, what defines a verb’s class are its bases. Endings themselves don’t change based on verb class.
In this lesson, we’ll look at the Ichidan verb class, commonly also known as “ru-verbs” as all these verbs end in /ru/ in their basic form. This class constitutes roughly half of all verbs in Japanese, making it incredibly important.
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 Shūshikei 終止形, it marks the end of a complete sentence/the predicate.
- Attributive Form: Known in Japanese as the Rentaikei 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 Ren’yōkei 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
Whereas adjectives require context to be interpreted in the future tense, verbs are more likely to go either way (polite or future) in the non-past form.
To use the plain non-past form, no conjugation is required, but there are two bases in play based on whether the verb is being used as a predicate (the predicative form 終止形) or as an attribute (the attributive form 連体形). As these forms are identical for Ichidan verbs, they are collectively referred to as the basic form (基本形).
| Meaning | Basic Form | Meaning | Basic Form |
| To see | Miru 見る | To borrow | Kariru 借りる |
| To wear | Kiru 着る | To remember | Oboeru 覚える |
| ①To get up②To happen | Okiru 起きる | To exist (animate objects) | Iru いる |
| To eat | Taberu 食べる | To open (trans.) | Akeru 開ける |
| To answer | Kotaeru 答える | To close (door, etc.) | Shimeru 閉める |
1. 看板を見る。
Kamban wo miru.
To look at a billboard.
2. 浴衣を着る。
Yukata wo kiru.
To wear a yukata.
3. 毎朝起きる。
Maiasa okiru.
i. To happen every morning
ii. To get up every morning.
4. 鳥がいる。
Tori ga iru.
There is a bird.
5. 野菜を食べる。
Yasai wo taberu.
To eat vegetables.
6. 食べる野菜 (Attributive Form)
Taberu yasai
Vegetables that (I/one) eat(s)
The Polite Non-Past Form w/ –masu ます
非過去の丁寧形 （～ます）
Conjugating verbs into polite speech involves the auxiliary verb –masu ます. One way 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 –masu ます we need to make other conjugations in polite speech.
–masu ます attaches to the “continuative form” (Ren’yōkei 連用形). As –masu 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 –ru, then you just add –masu ます.
| Meaning | Basic Form | Continuative Form | ＋-masu ます |
| To think | Kangaeru 考える | Kangae | Kangaemasu 考えます |
| To fall (intr.) | Ochiru 落ちる | Ochi | Ochimasu 落ちます |
| To close up/shut | Tojiru 閉じる | Toji | Tojimasu 閉じます |
| To lose | Makeru 負ける | Make | Makemasu 負けます |
| To show | Miseru 見せる | Mise | Misemasu 見せます |
7. ドアを閉じます。
Doa wo tojimasu.
I’ll close the door.
8. ちょっと考えます。
Chotto kangaemasu.
I’ll think about it.
9. 教科書を借ります。
Kyōkasho wo karimasu.
I’ll borrow the textbook.
Basic Form: Predicative vs. Attributive w/ –masu ます
We learned how desu です does not possess an attributive form, which prevents copula, adjective, and adjectival noun polite forms from directly modifying nouns. Verbs, however, do not use desu です. Instead, they use –masu ます, which DOES have both a predicative form (終止形) and an attributive form (連体形). However, its attributive form is rarely used because it need only be used once at the end of the sentence to mark politeness in everyday speech.
10a. よく借かりる教科書きょうかしょ 〇
Yoku kariru kyōkasho
10b. よく借かります教科書 X/△
Yoku karimasu kyōkasho
Textbook(s) that I often borrow
–masu ます only appears before nouns in extremely formal speech. Since you will only be creating sentences in typical polite speech, “-masu ます + noun” ought to be treated as a grammatical error.
The Plain Past Form w/ –ta 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 –ru る and add the auxiliary verb –ta た, which we learned already marks the past tense for other parts of speech.
| Meaning | Basic Form | Continuative Form | + –ta た |
| To find (trans.) | Mitsukeru 見つける | Mitsuke | Mitsuketa 見つけた |
| To collect | Atsumeru 集める | Atsume | Atsumeta 集めた |
| To get used to | Nareru 慣れる | Nare | Nareta 慣れた |
| To collapse | Taoreru 倒れる | Taore | Taoreta 倒れた |
Grammar Note: Because the predicative form (終止形) and attributive form (連体形) of the auxiliary verb –ta た are identical, past tense clauses can directly modify any noun phrase.
11. あの絵を見た。
Ano e wo mita.
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。
Kitte wo atsumeta.
I collected stamps.
14. クマが倒れた。
Kuma ga taoreta.
The bear collapsed.
15. だいぶ慣れた。
Daibu nareta.
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” – don’t exist in Japanese, and so both “past tense” and “perfect past tense” fall under the use of –ta た in Japanese.
The Polite Past Form w/ –mashita ました
丁寧語における過去形（～ました）
The continuative form of -masu ます (-mashi まし) is combined with –ta た to create –mashita 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 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 –mashita ました.
| Meaning | Basic Form → Continuative Form | +-mashita ました |
| To get | Eru 得る → E- | Emashita 得ました |
| To increase (intr.) | Fueru 増える → Fue- | Fuemashita 増えました |
| To plant | Ueru 植える → Ue- | Uemashita 植えました |
| To mix (trans.) | Mazeru 混ぜる → Maze- | Mazemashita 混ぜました |
| To line up (trans.) | Naraberu 並べる → Narabe- | Narabemashita 並べました |
Grammar Note: Although the auxiliary verb –ta 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, –mashita 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。
Ki wo uemashita.
I planted a tree.
17. 肩を並ならべました。
Kata wo narabemashita.
We lined up shoulders.
18. 人口が増えました。
Jinkō ga fuemashita.
The population increased/grew.
19. 調味料を混ぜました。
Chōmiryō wo mazemashita.
I mixed in spices.
20a. 混ぜた調味料 〇
Mazeta chōmiryō
20b. 混ぜました調味料 X
Mazemashita chōmiryō
Spice(s) that I mixed
The Plain Negative Form w/ –nai 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 adjective –nai 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 –ru. This identical to the continuative form (連用形), but this WON’T be the case with all the other verb classes.
| Meaning | Basic Form → Irrealis Form | ＋ –nai ない |
| To break (intr.) | Kowareru 壊れる → Koware- | Kowarenai 壊れない |
| To bathe in | Abiru 浴びる → Abi- | Abinai 浴びない |
| To get wet | Nureru 濡れる → Nure- | Nurenai 濡れない |
| To get off | Oriru 降りる → Ori- | Orinai 降りない |
| To seem/appear | Mieru 見える → Mie- | Mienai 見えない |
Grammar Note: Because the auxiliary adjective –nai 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’s of the negative form or some other conjugation, is that it plays the role of “who/what/where/when” when following a noun in English to mark the start of the modifier. It’s just that in Japanese the word order is opposite.
21. 引き戸が壊れない。
Hikido ga kowarenai.
The sliding door won’t break.
22. シャワーを浴びない。
Shawā wo abinai.
To not/will not take a shower.
23. 負けない。
Makenai.
I/we won’t lose.
24. 足が濡れないよ。
Ashi ga nurenai yo.
(Your) feet won’t get wet.
25. シャワーを浴びない子は意外と多い。
Shawā wo abinai ko wa igai-to ōiThere are surprisingly a lot of kids who don’t shower.
The Polite Negative Forms (-masen ません or –nai-desu 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: The irrealis form (未然形) of the auxiliary verb –masu ます is mase– ませ. It is paired with the auxiliary verb –n ん, which is the modern form of the original auxiliary verb for negation in Japanese. To summarize, the resultant ending is –masen ません, which follows neatly after the continuative form (連体形) as the pattern starts with –masu ます.
- Method 2: Once you conjugate the verb into its irrealis form (未然形), attach the auxiliary adjective –nai ない and follow it with the polite marker desu です. That’s all! If this seems simpler, it is. The consequence, however, is that it is very casual and NOT appropriate in formal settings. This includes texting, e-mails, etc. to people you ought to give proper respect to. Casual polite forms such as this are used when someone wishes to be more familiar with someone but aren’t ready to cross the line into plain speech.
Method 1: –masen ません (Proper Polite Form)
| Meaning | Basic Form → Continuative Form | ＋-masen ません |
| To change (trans.) | Kaeru 変える → Kae- | Kaemasen 変えません |
| To admit/recognize | Mitomeru 認める → Mitome- | Mitomemasen 認めません |
| To investigate | Shiraberu 調べる → Shirabe- | Shirabemasen 調べません |
| To sleep | Neru 寝る → Ne- | Nemasen 寝ません |
| To attach | Tsukeru 付ける → Tsuke- | Tsukemasen 付けません |
Method 2: –nai-desu ないです (Casual Polite Form)
| Meaning | Basic Form → Irrealis Form | ＋ –nai-desu ないです |
| To clear up/be sunny | Hareru 晴れる → Hare– | Harenai-desu 晴れないです |
| To be popular | Moteru モテる → Mote- | Motenai-desu モテないです |
| To leak | Moreru 漏れる → More- | Morenai-desu 漏れないです |
| To feel | Kanjiru 感じる → Kanji- | Kanjinai-desu 感じないです |
| To swell | Hareru 腫れる → Hare- | Harenai-desu 腫れないです |
Grammar Note: Although –masen ません does possess an attributive form (連体形), its use is limited for the same reasons as other conjugations of –masu ます. As such, for practical purposes, its placement before nominal phrases for everyday polite speech is considered ungrammatical. As for –nai-desu ないです, its use before nouns is impossible as desu です does not have an attributive form (連体形).
26. 今夜寝ません。
Kon’ya nemasen.
I won’t sleep tonight.
27. 何も感じません。
Nani mo kanjimasen.
I don’t feel anything.
28. （お）肉は食たべません。
(O-)niku wa tabemasen.
I don’t/won’t eat meat.
29. 神を信じません。
Kami wo shinjimasen.
I don’t believe in God/gods.
30. 内容は漏れないです。
Naiyō wa morenai desu.
(The) content won’t (get) leak.
31. 魚は食べないです。
Sakana wa tabenai desu.
I don’t eat fish.
The Plain Negative Past Form w/ –nakatta 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 adjective –nai ない must be conjugated into its past tense form. Connecting –nai ない to the verb itself is no different than as with the non-past tense: following the irrealis form (未然形).
To conjugate –nai ない into the past tense, you first use its continuative form (-nakari なかり) and combine it with the past tense marker –ta た, forming –nakatta なかった. When these two parts combine, a sound change occurs which reduces /ri/ to being a part of a double /t/.
| Meaning | Basic Form → Irrealis Form | ＋-nakatta なかった |
| To disappear | Kieru 消える → Kie– | Kienakatta 消えなかった |
| To forget | Wasureru 忘れる → Wasure– | Wasurenakatta 忘れなかった |
| To throw away | Suteru 捨てる → Sute– | Sutenakatta 捨てなかった |
| To exceed | Koeru 超える → Koe– | Koenakatta 超えなかった |
| To believe | Shinjiru 信じる → Shinji– | Shinjinakatta 信じなかった |
32. 消えなかった証拠
Kienakatta shōko
Evidence that didn’t disappear
33. 彼はごみを捨てなかった。
Kare wa gomi wo sutenakatta.
He didn’t throw away the trash.
34. 忘れなかったよ。
Wasurenakatta yo.
I didn’t forget.
The Polite Negative Past Forms (-masen-deshita or –nakatta desu)
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: As –masu ます is involved, you first conjugate the verb into its continuative form (連用形). From there, you conjugate –masu ます into its irrealis form (-masu ます → mase– ませ). Then, once you attach the negative auxiliary verb –n ん, things get tricky: you add –deshita でした directly to –masen ません. Because –masen ません is not the end of the sentence, –deshita でした is attaching itself to the attributive form (連体形) of-masen ません.
- Method 2: Treating the auxiliary adjective –nai ない as any other adjectival phrase, –nai ない becomes conjugated into its own continuative form (nakari– なかり) and is followed by –ta た to produce –nakatta なかった. Then, –desu です is attached to produce –nakatta-desu なかったです. The desu です is presumed to follow the predicative form (終止形) because it is solely a politeness marker and has lost its original grammatical restraints.
Method 1: –masendeshita ませんでした (Proper Polite Form)
| Meaning | Basic Form → Continuative Form | ＋ –masen-deshita ませんでした |
| To begin/start (trans.) | Hajimeru 始める → Hajime- | Hajimemasen-deshita 始めませんでした |
| To leave/exit | Deru 出る → De- | Demasen-deshita 出ませんでした |
| To finish (trans.) | Oeru 終える → Oe- | Oemasen-deshita 終えませんでした |
| To throw | Nageru 投げる → Nage- | Nagemasen-deshita 投げませんでした |
| To lower (trans.) | Sageru 下げる → Sage- | Sagemasen-deshita 下げませんでした |
Method 2: –nakatta-desu なかったです (Casual Polite Form)
| Meaning | Basic Form → Irrealis Form | ＋ –nakatta-desu なかったです |
| To run away | Nigeru 逃げる → Nige– | Nigenakatta-desu 逃げなかったです |
| To hurt (trans.) | Kizutsukeru 傷つける → Kizutsuke– | Kizutsukenakatta-desu 傷つけなかったです |
| To carry forward (trans.) | Susumeru 進める → Susume– | Susumenakatta-desu 進めなかったです |
| To compile | Matomeru 纏める → Matome– | Matomenakatta-desu 纏めなかったです |
| To cool down (intr.) | Sameru 冷める → Same– | Samenakatta-desu 冷めなかったです |
Grammar Note: The negative past is never seen in polite speech modifying a noun. This is because both methods end in a form of desu です. Thus, either way, placing these forms before a noun would be a grammatical error.
35. 話題を変えません-でしたよ。
Wadai wo kaemasendeshita.
I didn’t change the topic.
36. ピザを食べませんでした。
Piza wo tabemasen-deshita.
I didn’t eat pizza.
37. なかなか焦げませんでした。
Nakanaka kogemasen-deshita.
It wouldn’t quite get charred.
38. 特に調べませんでした。
Toku ni shirabemasen-deshita.
I didn’t particularly check/investigate it.
39a. 食たべなかったピザ 〇
Tabenakatta piza
39b. 食たべませんでしたピザ X
Tabemasen-deshita piza
The pizza I didn’t eat
40. 今日は晴れなかったです。
Kyō wa harenakatta-desu.
It didn’t clear up today.
41. コイは逃げなかったです。
Koi wa nigenakatta-desu.
The koi fish didn’t swim away.
42. お風呂はなかなか冷めなかったです。
O-furo wa nakanaka samenakatta-desu.
The bath didn’t quite cool down.