Japanese has a rich conjugation system, comparing English. ( But it is not as rich as Romance languages. ) This chapter introduces whole conjugation tables of Japanese verbs. To understand all is unnecessary for beginners of Japanese. However, to know the outline is very useful for them, since you can imagine what Japanese can express by these table.

The Verbal System

			plain				polite
			week verb	strong verb	adjectival verb	copula (da)	copula (de-su)	verb (-ma-su)
Inflection	present	indicative	-ru	-u	-i	da	-su
		enumeration				nari
		conditional	-reba	-eba	-kereba	nara
		imperative	-ro	-e				-se (*3)
		subjunctive	-you	-ou	-karou (*2)	darou	-shou
		participle	[use stem]	-i	-ku	ni
	past	indicative	-ta		-katta	datta	-shita
		participle	-te		-kute	de	-shite (*3)
	negative	participle	-zu	-azu				-sen (*4)
Derivative	negative verb		-na-i	-ana-i
	causative verb		-sase-ru	-ase-ru
	passive verb		-rare-ru	-are-ru
	potential verb		-(ra)re-ru (*1)	-e-ru

• Japanese has 6 types of conjugation excluding irregular types. They are weak verbs for verbs whose stems end with a vowel, strong verbs for verbs whose stems end with a consonant, adjectival verbs, the copula, polite verbs which consist of verbs followed by a polite auxiliary verb and the polite copula which is the polite correspondence of the copula.
• Japanese has 3 layers in the verbal system. The upper layer classifies the inflections and the derivatives. The second layer classifies the past and the present. The lower layer has 6 forms. Then it has one trace for the negative present by historical reasons.
• Japanese verbs have 4 derivative verbs. They are negative verbs which is conjugated as an adjectival verb, causative verbs, passive verbs and potential verbs. All of the last 3 derivative verbs are conjugated as weak verbs.
• Japanese has 2 tenses which are the present and the past. The present includes not only the literal meaning but also the future, the habitual action, the nature rules and the historical present. The past also includes various meanings as well as the literal meaning. It includes the perfect and the confirmation. These two tenses have an influence on subordinate clauses.
• Japanese has 6 forms in the lower layers. They are 3 predicative forms and 3 conjunctive forms. 3 predicative forms correspond to 3 moods, the indicative, the imperative and the subjunctive. Especially, the present indicative and the past indicative are simply called the present and the past as the abbreviation. On the other hand, the other 3 conjunctive forms are the enumeration, the conditional and the participle. In classic Japanese, it had almost complete set of 6 forms for the past and the negative as well as the present. However, they are simplified and isolated to another words, so the total number of the inflections is 9, which are 6 for the present, 2 for the past, 1 for the negative in modern Japanese. When you express all sets of forms for the past and the negative, you use inflectional particles, which come form the inflections of the copulas, with another forms and another derivative verbs correspondingly.
• (*1) The potential derivative verbs of weak verbs sometimes omit their sound from "-rareru" to "-reru" in colloquial conversation. It is called "ra-nuki (ra-omission)" in Japanese.
• (*2) The subjunctive inflection of adjectival verbs is usually replaced with "-i darou", which is the present inflection followed by the subjunctive of the copula. For polite contexts, "-i deshou" is used.
• (*3) These inflections are not used generally. They are mainly used in classic documents, formal documents or idiomatic expressions, when you come across them.
• (*4) The negative form of the polite verb is not the participle but the indicative.
• In some dialects and some speeches, the negative verb "-na-i" is abbreviated as follows.
  • the negative present indicative: "-na-i" → "-n" or "-nu".
  • the negative present conditional: "-na-kereba" → "-neba".

Inflectional particles are not included in parts of speech. They fill the lost forms of the verbal system, such as the past enumeration as so on.

• the present enumeration: the present + " nari", which is the enumeration of the copula.
• the present conditional: the present + " nara", which is the conditional of the copula.
• the present subjunctive: the present + " darou", which is the subjunctive of the copula.
• the past enumeration: the past + " nari", which is the enumeration of the copula.
• the past conditional: the past + " nara", which is the conditional of the copula.
• the past subjunctive: the past + " darou", which is the subjunctive of the copula.
• the negative imperative: the present + " na", which is a special particle to express prohibition.
• the negative subjunctive: the present + " mai", which is a special particle to express negative intent mainly.
• the negative past participle: the negative verb + " de", which is the past participle of the copula.

Inflectional Particles

		particle	plain				polite
			week verb	strong verb	adjectival verb	copula (da)	copula (de-su)	verb (-ma-su)
present	enumeration	nari	-ru nari	-u nari	-i nari	nari	-su nari
	conditional	nara	-ru nara	-u nara	-i nara	nara	-su nara
	subjunctive	darou	-ru darou	-u darou	-i darou	darou
past	enumeration	nari (*1)	-ta nari -tari		-katta nari -kattari	datta nari dattari	-shita nari -shitari
	conditional	nara (*2)	-ta nara -tara		-katta nara -kattara	datta nara dattara	-shita nara -shitara
	subjunctive	darou (*3)	-ta darou -tarou		-katta darou -kattarou	datta darou dattarou
negative	imperative	na	-ru na	-u na
	subjunctive	mai (*4)	-(ru) mai	-u mai				-su mai
negative past	participle	de	-na-i de	-ana-i de

• (*1) The past enumeration usually drops "na" in "nari". So the popular forms are "-tari", "-kattari", "-dattari" and so on.
• (*2) The past conditional usually drops "na" in "nara". So the popular forms are "-tara", "-kattara", "-dattara" and so on.
• (*3) The past subjective does not usually drop "da" in "darou".
• (*4) The negative subjective usually drops "ru" in "-ru mai", when it follows week verbs.

Inflectional polite particles add polite meanings to inflections. They come from the inflections of the polite copula.

• the polite present: the present + " desu", which is the present of the polite copula.
• the polite present subjunctive: the present + " deshou", which is the subjunctive of the polite copula.
• the polite past: the past + " desu", which is the present of the polite copula.
• the polite past subjunctive: the past + " deshou", which is the subjunctive of the polite copula.

Inflectional Polite Particles

		particle	plain
			week verb	strong verb	adjectival verb	copula (da)
present	indicative	desu			-i desu
	subjunctive	deshou	-ru deshou	-u deshou	-i deshou
past	indicative	desu	-ta desu (*1)		-katta desu	datta desu (*2)
	subjunctive	deshou	-ta deshou		-katta deshou	datta deshou

• (*1) This form "ta desu" is not formal in writing. It is mainly used in colloquial conversations instead of the formal form "-mashita".
• (*2) This form "datta desu" is not formal in writing. It is mainly used in colloquial conversations instead of the formal form "deshita".

Sound Changes of Strong Verbs Combination Stem + Inflection Real Forms K -k + t- → -it- kak + t- → kait- kàita, kàite, kàitara, kàitari R -r + t- → -tt- kar + t- → katt- kátta, kátte, káttàra, káttàri S -s + t- → -shit- kas + t- → kashit- káshita, káshite, káshitàra, káshitàri T -t + t- → -tt- kat + t- → katt- kàtta, kàtte, kàttara, kàttari W -w + t- → -tt- kaw + t- → katt- kátta, kátte, káttàra, káttàri B -b + t- → -nd- ukab + t- → ukand- úkanda, úkande, úkandàra, úkandàri G -g + t- → -id- kag + t- → kaid- káida, káide, káidàra, káidàri M -m + t- → -nd- kam + t- → kand- kànda, kànde, kàndara, kàndari N -n + t- → -nd- shin + t- → shind- shínda, shínde, shíndàra, shíndàri S -s + i → -shi kas + i → kashi káshi T -t + i → -chi kat + i → kachi kàchi T -t + u → -tsu kat + u → katsu kàtsu W -w + i → -i kaw + i → kai kái W -w + u → -u kaw + u → kau káu W -w + e- → -e- kaw + e- → kae- káe, káèba, káeru W -w + ou → -ou kaw + ou → kaou káòu

A Dictionary Japanese Kana English kàku かく to write káru かる to cut kásu かす to lend kàtsu かつ to win káu かう to buy úkabu うかぶ to float kágu かぐ to smell kàmu かむ to bite shínu しぬ to die

• Strong verbs whose stems end with a consonant have some sound chagens mainly for their past and past participle, because Japanese, which is an open syllabic language, needs special considerations when the last consonant of a verbal stem is followed by the inflections.
• The first 11 patterns are caused by double consonants, the last 7 patterns are caused by palatalization or omission.

Irregular Verbs Modern S Classic S Classic Z K Inflection present indicative -suru -zuru kùru conditional -sureba -zureba kùreba imperative -shiro -jiro kòi subjunctive -shiyou -jiyou kóyòu participle -shi -ji kì past indicative -shita -jita kìta participle -shite -jite kìte negative participle -sezu -zezu kòzu Derivative negative verb -shina-i -jina-i kòna-i causative verb -sase-ru -sesase-ru -zesase-ru kósasè-ru passive verb -sare-ru -serare-ru -zerare-ru kórarè-ru potential verb -deki-ru (*1) -serare-ru -zerare-ru kó(ra)rè-ru the present enumeration: the present + " nari" the past enumeration: the past + "ri" ( the past + " nari" is an alternation. ) the past conditional: the past + "ra" ( the past + " nara" is an alternation. ) the negative imperative: the present + " na" the negative subjunctive: the present + " mai" ( Weak verbs drop "ru" preceding " mai". ) the negative past participle: the present of negative verbs + " de"

A Dictionary Japanese Kana English súru する to do dékìru できる to be able kùru くる to come àisu あいす to love nèssu ねっす to heat kánjìru かんじる to feel shínjìru しんじる to believe ákìru あきる to get tired of ákeru あける to open ákaru-i あかるい bright

• Japanese has 2 types of irregular conjugation ( Modern S, K ) for primitive verbs. and 3 types ( Modern S, Classic S, Classic Z ) for compound verbs.
• Classic S appears in one Chinese character followed by "suru". However, This type is merged into a strong verb, for example, "ái-sùru" into "àis-u", "nés-suru" into "néss-u". You do not have to speak Classic S, although you have to understand it when you hear it.
• Classic Z appears in one Chinese character followed by "zuru" voiced from "suru". However, This type is merged into a weak verb, for example, "kán-zùru" into "kán-jìru", "shín-zùru" into "shín-jìru". You do not have to speak Classic Z, although you have to understand it when you hear it.
• Irregular Verb K contains only one word "kùru"
• Modern S is frequently used by verbal nouns combined with "suru".
• (*1) The potential derivative verb of "suru" is perfectly a different originated verb from "suru". The verb is "dekiru" conjugated as a weak verb.

Conjugation Table - 1

			Weak Verbs				Irregular Verbs
			I		E		Modern S		K
dictionary			akiru		akeru		suru		kuru
Inflection	present	indicative	aki	-ru	ake	-ru	su	-ru	ku	-ru
		conditional		-reba		-reba		-reba		-reba
		imperative		-ro		-ro	shi	-ro	ko	-i
		subjunctive		-you		-you		-you		-you
		participle		-		-		-	ki	-
	past	indicative		-ta		-ta		-ta		-ta
		participle		-te		-te		-te		-te
	negative	participle		-zu		-zu	se	-zu	ko	-zu
Derivative	negative verb			-na-i		-na-i	shi	-na-i		-na-i
	causative verb			-sase-ru		-sase-ru	s	-ase-ru		-sase-ru
	passive verb			-rare-ru		-rare-ru		-are-ru		-rare-ru
	potential verb			-(ra)re-ru		-(ra)re-ru	deki-ru			-(ra)re-ru
the present enumeration: the present + " nari" the past enumeration: the past + "ri" ( the past + " nari" is an alternation. ) the past conditional: the past + "ra" ( the past + " nara" is an alternation. ) the negative imperative: the present + " na" the negative subjunctive: the present + " mai" ( Weak verbs drop "ru" preceding " mai". ) the negative past participle: the present of negative verbs + " de"

Conjugation Table - 2

			Strong Verbs
			K		R		S		T		W
dictionary			kaku		karu		kasu		katsu		kau
Inflection	present	indicative	kak	-u	kar	-u	kas	-u	kats	-u	ka	-u
		conditional		-eba		-eba		-eba	kat	-eba		-eba
		imperative		-e		-e		-e		-e		-e
		subjunctive		-ou		-ou		-ou		-ou		-ou
		participle		-i		-i	kash	-i	kach	-i		-i
	past	indicative	kai	-ta	kat	-ta	kashi	-ta	kat	-ta	kat	-ta
		participle		-te		-te		-te		-te		-te
	negative	participle	kak	-azu	kar	-azu	kas	-azu		-azu	kaw	-azu
Derivative	negative verb			-ana-i		-ana-i		-ana-i		-ana-i		-ana-i
	causative verb			-ase-ru		-ase-ru		-ase-ru		-ase-ru		-ase-ru
	passive verb			-are-ru		-are-ru		-are-ru		-are-ru		-are-ru
	potential verb			-e-ru		-e-ru		-e-ru		-e-ru	ka	-e-ru
the present enumeration: the present + " nari" the past enumeration: the past + "ri" ( the past + " nari" is an alternation. ) the past conditional: the past + "ra" ( the past + " nara" is an alternation. ) the negative imperative: the present + " na" the negative subjunctive: the present + " mai" ( Weak verbs drop "ru" preceding " mai". ) the negative past participle: the present of negative verbs + " de"

Conjugation Table - 3

			Strong Verbs
			B		G		M		N
dictionary			ukabu		kagu		kamu		shinu
Inflection	present	indicative	ukab	-u	kag	-u	kam	-u	shin	-u
		conditional		-eba		-eba		-eba		-eba
		imperative		-e		-e		-e		-e
		subjunctive		-ou		-ou		-ou		-ou
		participle		-i		-i		-i		-i
	past	indicative	ukan	-da	kai	-da	kan	-da		-da
		participle		-de		-de		-de		-de
	negative	participle	ukab	-azu	kag	-azu	kam	-azu		-azu
Derivative	negative verb			-ana-i		-ana-i		-ana-i		-ana-i
	causative verb			-ase-ru		-ase-ru		-ase-ru		-ase-ru
	passive verb			-are-ru		-are-ru		-are-ru		-are-ru
	potential verb			-e-ru		-e-ru		-e-ru		-e-ru
the present enumeration: the present + " nari" the past enumeration: the past + "ri" ( the past + " nari" is an alternation. ) the past conditional: the past + "ra" ( the past + " nara" is an alternation. ) the negative imperative: the present + " na" the negative subjunctive: the present + " mai" ( Weak verbs drop "ru" preceding " mai". ) the negative past participle: the present of negative verbs + " de"

Conjugation Table - 4

			Adjectival Verbs		Copula	Polite Copula		Polite Verb
dictionary			akaru-i		da	desu		-masu
Inflection	present	indicative	akaru	-i	da	de	-su	-ma	-su
		enumeration		-i nari	nari		-su nari		-su nari
		conditional		-kereba	nara		-su nara		-su nara
		subjunctive		-karou	darou		-shou		-shou
		participle		-ku	ni
	past	indicative		-katta	datta		-shita		-shita
		participle		-kute	de		-shite		-shite
	negative	indicative							-sen
the past enumeration: the past + "ri" ( the past + " nari" is an alternation. ) the past conditional: the past + "ra" ( the past + " nara" is an alternation. ) ( only "-masu" ) the negative subjunctive: the present + " mai" ( Weak verbs drop "ru" preceding " mai". )

• Please refer to "Recessive Stems" to know how to classify strong verbs and weak verbs.
• Please click this Japanese document, if you are interested in a conjugation table written in Japanese.