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　　In Japanese, there is a handful of verb classes that differ in conjugation. In this lesson, we will specifically only learn about verbs called "ru る verbs," more specifically called Ichidan 一段 verbs. This class constitutes half of all verbs in Japanese.

　　Before we learn about these verbs, let's go over some basic grammatical terminology. 

Just as with adjectives and adjectival nouns, the basic tenses of Japanese are non-past (present or future) and past. Although tense may not be the best word to describe what goes on in Japanese, we'll stick to it to have things feel more familiar.

Plain Non-Past Form: No Conjugation 

Unlike the previous parts of speech we've covered, no conjugation is ever required to use the non-past tense in plain speech. This includes times when you use a verb to modify a noun. That means you won't have to learn any rules like da だ becoming na な.  

It is when you use polite speech that goes beyond the basic form that you begin to conjugate. Nevertheless, as you will see, the non-past form can also stand for the infinitive form, which is the "to..." form of verbs in English. This means quite a few slightly different things can be expressed just with the basic form of a verb.

1. 看板かんばんを見みる。
Kamban wo miru.
To look at a billboard.

2. 汚きたない服ふくを着きる。
Kitanai fuku wo kiru.
To wear dirty clothes.

3. 毎朝起まいあさおきる。
Maiasa okiru.
To happen every morning/To get up every morning.

4. 時間じかんが過すぎる。
Jikan ga sugiru.
Time passes.

5. 野菜やさいを煮にる。
Yasai wo niru.
To simmer vegetables.

 Polite Non-Past Form: -masu ます

To make an Ichidan 一段 verb polite in the non-past tense, drop ru る and add -masu ます.  

6. ドアを閉(と)じます。
Doa wo tojimasu.
I’ll close the door.

7. ちょっと考(かんが)えます。
Chotto kangaemasu.
I’ll think about it.

8. 教科書きょうかしょを借かります。
Kyōkasho wo karimasu.
I’ll borrow the textbook. 

Usage Note: This form almost always cannot modify nouns. Meaning, you can't place it before a noun for the purpose of modifying said noun. To modify nouns with verbs in the non-past tense, you must use the plain form without -masu ます. 

Ex. よく借(か)りる教科書(きょうかしょ)　〇
Yoku kariru kyōkasho
よく借(か)ります教科書(きょうかしょ)　X
Yoku karimasu kyōkasho
Textbook(s) that I often borrow 

Plain Past Form: -ta た

To make an Ichidan 一段 verb past tense in plain speech, drop ru る and add -ta た. 

Usage Note: This form can also be used to modify nouns without any change in form. Most conjugations are able to do so as long as they are not in their polite forms.

9. あの絵(え)を見(み)た。
Ano e wo mita.
I saw that picture.

10. 切手きってを集あつめた。
Kitte wo atsumeta.
I collected stamps.

11. クマが倒(たお)れた。
Kuma ga taoreta.
The bear collapsed. 

12. だいぶ慣なれた。
Daibu nareta.
I've gotten fairly used to it. 

Grammar Note: Perfect past tense involving "to have..." in English is usually translated with the past tense. 

Polite Past Form: -mashita ました 

To make an Ichidan 一段 verb past tense in polite speech, drop ru る and add -mashita ました. 

13. 木きを植うえました。
Ki wo uemashita.
I planted a tree.

14. 言葉ことばを並ならべました。
Kotoba wo narabemashita.
I lined up the words.

15. 人口(じんこう)が増(ふ)えました。
Jinkō ga fuemashita.
The population increased/grew.

16. 調味料(ちょうみりょう)を混(ま)ぜました。
Chōmiryō wo mazemashita.
I mixed in spices. 

Usage Note: Usually, this form cannot modify nouns. Meaning, you can't place it before a noun for the purpose of modifying said noun. To modify nouns with verbs in the past tense, you must use the plain form -ta た. 

Ex. 混(ま)ぜた調味料(ちょうみりょう)　〇
Mazeta chōmiryō
混(ま)ぜました調味料(ちょうみりょう) X
Mazemashita chōmiryō
Spice(s) that I mixed  

Plain Negative Form: -nai ない  

To make an Ichidan 一段 verb negative in plain speech, drop ru る and add -nai ない. 

Usage Note: This form can also be used to modify nouns without any change in form. Most conjugations are able to do so as long as they are not in their polite forms. 

17. 引ひき戸どが壊こわれない。
Hikido ga kowarenai.
The sliding door won’t break.

18. シャワーを浴(あ)びない。
Shawā wo abinai.
To not/will not take a shower.

19. 僕ぼくは負まけない。(Male speech)
Boku wa makenai.
I won’t lose.

20. 足あしが濡ぬれない。
Ashi ga nurenai.
One’s feet won’t get wet. 

21. 負まけない心こころ
Makenai kokoro
A heart that won’t lose 

Polite Negative Form: -masen ません 

To make an Ichidan 一段 verb negative in polite speech, drop ru る and add -masen ません. 

Usage Note: This form almost always cannot modify nouns. Meaning, you can't place it before a noun for the purpose of modifying said noun. To modify nouns with verbs in the negative, you must use the plain form -nai ない.  

22. 今夜こんや寝ねません。
Kon’ya nemasen.
I won’t sleep tonight.

23. 何なにも感かんじません。
Nani mo kanjimasen.
I don’t feel anything.

24. （お）肉(にく)は食(た)べません。
(O-)niku wa tabemasen.
I don’t/won’t eat meat.

25. 神かみを信しんじません。
Kami wo shinjimasen.
I don’t believe in God. 

Usage Note: This form almost always cannot modify nouns. Meaning, you can't place it before a noun for the purpose of modifying said noun. To modify nouns with verbs in the negative, you must use the plain form -nai ない.   

Ex. 食(た)べない（お）肉にく　〇      
Tabenai (o-)niku
食たべません（お）肉にく　X       
Tabemasen (o-)niku
Meat that I don't/won't eat

Plain Negative Past Form: -nakatta なかった 

To make an Ichidan 一段 verb negative past in plain speech, drop ru る and add -nakatta なかった. 

Usage Note: This form can also be used to modify nouns without any change in form. Most conjugations are able to do so as long as they are not in their polite forms. 

26. 消きえなかった証拠しょうこ
Kienakatta shōko
Evidence that didn’t disappear

27. 彼かれはごみを捨すてなかった。
Kare wa gomi wo sutenakatta.
He didn’t throw away the trash.

28. 忘わすれなかったよ。
Wasurenakatta yo.
I didn’t forget.

Particle Note: The particle yo よ adds exclamation to the sentence.

Polite Negative Past Form: -masendeshita ませんでした 

To make an Ichidan 一段 verb negative past in polite speech, drop ru る and add -masendeshita ませんでした. 

29. 話題わだいを変かえませんでした。
Wadai wo kaemasendeshita.
I didn't change the topic. 

30. ピザを食べませんでした。
Piza wo tabemasendeshita.
I didn't eat pizza. 

31. なかなか焦(こ)げませんでした。
Nakanaka kogemasendeshita.
It didn’t really get charred.

32. 特とくに調しらべませんでした。
Toku ni shirabemasendeshita.
I didn’t particularly check/investigate it.

Usage Note: This form cannot modify nouns. Meaning, you can't place it before a noun for the purpose of modifying said noun. To modify nouns with verbs in the negative past, you must use the plain form -nakatta なかった. 

Ex.  食(た)べなかったピザ
Tabenakatta piza
食(た)べませんでしたピザ
Tabemasendeshita piza
The pizza I didn’t eat 

Alternative Polite Negative & Neg-Past Forms: -nai desu & -nakatta desu ないです・なかったです 

To make an Ichidan 一段 verb negative or negative past in polite yet casual speech, drop ru る and add -nai desu ないです or nakatta desu なかったです respectively. 

33. 内容(ないよう)は漏(も)れないです。
Naiyō wa morenai desu.
(The) content won’t leak.

34. 今日(きょう)は晴(は)れなかったです。
Kyō wa harenakatta desu.
It didn’t clear up today. (Weather)

35. 魚(さかな)は食(た)べないです。
Sakana wa tabenai desu.
I don’t eat fish. 

Usage Note: These forms cannot modify nouns. To modify nouns with verbs in the negative or negative past, you must use their plain forms -nai ない and -nakatta なかった respectively.  

Ex. もてない男 〇
Motenai otoko
もてないです男 X
Motenai desu otoko
A man who isn’t popular

Conjugation Recap 

As review, here are the conjugations you learned in this lesson with the verbs miru 見る (to see) and taberu 食べる (to eat).