Plain form is also called dictionary form and it is just like “masu” form but is used in casual, informal situations. Plain form is the present/future tense and is pretty important because you use this as a basis to create other verb forms (like past and negative).

You can practice all of these using the J-Talk Online Memrise course Beginners Japanese Grammar 1 (JLPT N5 Grammar). See last week’s post on Studying Japanese Grammar for tips on ways to learn grammar.

Beginners Japanese Grammar

But the first thing you need to know about plain form are the 3 groups.

Group 1 or “u verbs” 

These are words that have an “u” sound at the end. When you turn a “masu” form into plain form the “I” changes to the “u” for group 1 verbs. Such as the following.

Beginners Japanese Grammar

いきます ikimasu  -> いく iku   = to go

あらいます araimasu -> あらう arau   = to wash

たちます tachimasu -> たつ tatsu   = to stand

はなします hanashimasu -> はなす hanasu   = to talk

かえります kaerimasu -> かえる kaeru   = to go home

はしります hashirimasu -> はしる hashiru   = to run

Group 2 or “ru verbs” 

This group can be distinguished by the “e” sound in “masu form”. To change it to plain you just remove the “masu” to make it into a stem and add “ru”. These verbs are easier because unlike Group 1 the stem doesn’t change at all.

Beginners Japanese Grammar

たべます tabemasu -> たべる taberu   = to eat

しめます shimemasu -> しめる shimeru   = to shut

ねます nemasu -> ねる neru   = to sleep

いれます iremasu -> いれる ireru   = to put in

I mentioned that group 1 verbs can be recognised by the “i” before the “masu”. There are a few group 2 verbs that have this pattern too, you just have to remember them and get used to using them as group 2 and not group 1 verbs:

います imasu – いる iru   = to be

かります karimasu –  かりる kariru   = to lend

おきます okimasu = おきる okiru   = to wake/get up

 

Group 3 (irregular verbs) 

 There are only 2 verbs. They are irregular because they change differently from groups 1 and 2.

 します shimasu -> する suru   = to do

 きます kimasu -> くる kuru   = to come

As I said, these groups are particularly important to learn because each group changes differently depending on what you’re turning the verb into. The following explains past tense and negative to illustrate these changes. Pay particular attention to group 1/U verbs as they change the most.


Past Plain (た form)

Plain past form is done by removing “ru” and adding “ta” to the end of the word. But this is different for each group.

Group 1 

 This is a bit of a weird one because depending on the “u” ending they get turned into past tense in different ways.

Beginners Japanese Grammar
This is from a great site called PuniPuni Japan which has explanations of various grammar points with useful pictures and videos!

(u), (tsu), or (ru) change to った. Such as:

かう kau -> かった ka-ta   = to buy / bought

まつ matsu -> まった ma-ta   = to wait / waited

かえる kaeru -> かえった kae-ta   = to go home / went home

(mu), (nu), or (bu) change to んだ. Such as:

 よむ yomu -> よんだ yonda   = to read / read

 しぬ shinu -> しんだ shinda   = to die / died

 あそぶ asobu -> あそんだ asonda   = to play / played

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And (ku) changes to いた. Such as:

 かく kaku -> かいた kaita   = to write / wrote

EXCEPT いく (to go) which changes to いった (went).

 

 Group 2 

 This is simple as you don’t change the stem of the word and just add . Such as:

 たべる taberu -> たべた tabeta   = to eat / ate

 

 Group 3 

 する suru -> した shita   = to do / did

 くる kuru -> きた kita   = to come / came

You can make these more polite by adding “desu”. I.e いったです instead of いきました is slightly less formal. BUT NEVER mix and でした (i.e いったでした)! And NEVER mix plain and です (i.e いくです)!

  

Negative Plain (ない form)

To make a word negative in plain form you add “nai” ない

Group 1 

 For group 1/”u” verbs you change the “u” to an “a” sound and add “nai”.

 いく iku -> いかない ikanai   = to go / do not go

 あそぶ asobu -> あそばない asobanai   = to play / do not play

Group 2

 Remove the “ru” of the “ru” verb and just add nai.

 たべる taberu -> たべない tabenai   = to eat / do not eat

 しめる shimeru -> しめない shimenai   = to close / do not close

Group 3

 Irregulars have their own changes. Be careful of “kuru” because it changes to “KOnai

 する suru -> しない shinai   = to do / do not do

 くる kuru -> こない konai   = to come / do not come

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You can practice all of these using the J-Talk Online Memrise course Beginners Japanese Grammar 1 (JLPT N5 Grammar)