Japanese consonant and vowel verbs

The Japanese language has two types of regular verbs that involve the stem, and can be referred to as Japanese consonant and vowel verbs.

Verb groups

The two groups of verbs are:

1. consonant-stem, godan-katsuyō (五段活用^?, "5-class conjugation"), Group I, or -u verbs; and
2. vowel-stem, ichidan-katsuyō (一段活用^?, "1-class conjugation"), Group II, or -ru verbs.

Most verbs are consonant-stem, but vowel-stem verbs are also common, hence the numbering "Group I" (consonant-stem, more common) and "Group II" (vowel-stem, less common). Sometimes categorization is expanded to include "Group III" (special cases) for the irregular verbs する suru and 来る kuru; note however that there are other Japanese irregular verbs, though they are generally only slightly irregular.

Consonant-stem verbs end in -u (-au, -iu, -uu, -ou), -ku, -gu, -su, -tsu, -nu, -bu, -mu or -ru, but not -eu, -zu, -dzu, -fu, -pu, or the defective columns -yu or -wu.

All vowel-stem verbs end in either -iru or -eru. However, not all verbs ending in -iru or -eru are vowel-stem verbs; for example, hashiru, "run", is a consonant-stem verb. Verbs ending in -aru, -uru and -oru also exist, and are all consonant-stem.

The Japanese names ("5-class" and "1-class") are based on the number of vowel suffixes used to form verb roots for conjugations. Classical Japanese had more verb groups (such as 2-class and 4-class) which are archaic in Modern Japanese.

Conjugation

Main article: Japanese verb conjugations

See also: Japanese grammar § Verbs

Consonant-stem verbs conjugate differently from the vowel-stem verbs. Consonant-stem verbs conjugate after a consonant, and vowel-stem verbs conjugate after a vowel, as can be seen in the following examples:

	consonant-stem		vowel-stem
Plain form	yom.u ("read") 読む	hashir.u ("run") 走る	mi.ru ("see") 見る	tabe.ru ("eat") 食べる
Negative	yom.anai 読まない	hashir.anai 走らない	mi.nai 見ない	tabe.nai 食べない
Polite form	yom.imasu 読みます	hashir.imasu 走ります	mi.masu 見ます	tabe.masu 食べます
Potential form	yom.eru 読める	hashir.eru 走れる	mi.rareru 見られる¹ ²	tabe.rareru 食べられる¹
Volitional form	yom.ou 読もう	hashir.ou 走ろう	mi.you 見よう¹ ²	tabe.you 食べよう¹

1. Note that colloquially the ら ra is dropped meaning these two become mireru and tabereru.
   
2. Can also be written as mi.eru. The difference is like the difference between "can see" and "can be seen." Two consonant-stems that are also irregular are ik.eru/ik.areru ("can go") and kik.eru/kik.oeru ("can hear"). Other irregular verbs are suru->dekiru ("can do") and kuru->korareru ("can come").

Consonant-stem verbs ending in -u (-au, -iu and -ou) may not appear to conjugate "after a consonant"; for example, the polite form of kau (買う, "buy") is kaimasu (ka.u → ka.imasu). However, the stem is in these cases technically considered to end in the consonant w. The w is normally suppressed, but surfaces in the negative form, as in kaw.anai ("does not buy"). Traditionally these verbs ended in -hu, which is still seen on occasion in historical kana usage, and thus unambiguously ended in h.

Terminology

The terms "consonant-stem" and "vowel-stem" come from considering the invariant part of the verb (the verb stem) on the basis of phonemes – concretely, by writing in rōmaji. This is an abstract perspective, as the consonant stem itself never occurs independently, but only with a following vowel, as Japanese words are formed of morae – concretely, writing in kana. For example, while the stem of yomu is yom-, the bare *yom is not an independent word.

The standard Japanese terms, ichidan and godan, literally "one row" and "five rows", more formally monograde and pentagrade, correspond to the number of different morae (kana) that appear in the stem forms of the verb, which are then optionally combined with a suffix to form a conjugated word. Formally, verbs are classified by which column of the gojūon their stem ends in, with vowel stem verbs further distinguished into i and e type. For example, 読む yomu is of マ行五段活用 ma-gyō go-dan katsuyō "ma-column five-row conjugation" type, as its stem form end in each of the five rows of the ま column, namely まみむめも:

• 読ま よま yoma- as in yomanai (negative, irrealis),
• 読み よみ yomi- as in yomimasu (polite non-past),
• 読む よむ yomu- as in yomu (plain non-past; dictionary form),
• 読め よめ yome- as in yomeba (conditional),
• 読も よも yomo- as in yomō (yomou) (hortative/volitional).

Note that the volitional o stem is historically the negative a stem with euphonic sound change – and the o stem is only used for the volitional form – so these verbs were traditionally called 四段 yodan "four-row, tetragrade", omitting the o form.

While the above uses are the most common uses of the respective stems, they are used in various other ways, particularly the i stem – for example 読み物 yomi-mono "reading material"; compare 食べ物 tabe-mono "food" for vowel stem.

By contrast, vowel stem verbs have a single stem form, ending either in i or e, accordingly as -iru or -eru. These are referred to respectively as 上一段 kami ichi-dan "upper one-row" and 下一段 shimo ichi-dan "lower one-row", due to i being above e in the aiueo vowel ordering. In full terminology, the column of the final kana is also listed. For 見る みる miru is of マ行上一段活用 ma-gyō kami ichidan katsuyō "ma-column upper one-row conjugation" type and has stem:

• 見 み mi-

while 食べる たべる taberu is of バ行下一段活用 ba-gyō shimo ichidan katsuyō "ba-column lower one-row conjugation" and has stem:

• 食べ たべ tabe-

In Japanese dictionaries, in the readings of conjugable words the stem and the inflectional suffix are separated by a dot (・), as in 赤い あか・い aka.i "red". This is used to distinguish verb type, with consonant stem verbs having only the last kana treated as suffix, while in vowel stem verbs the last two kana are treated as suffix. The column 行 of the conjugation form corresponds to the kana immediately after the dot. For example:

• 帰る かえ・る kae.ru "return" – consonant stem ラ行五段
• 変える か・える ka.eru "change" – vowel stem ア行下一段

Note that for one-row verbs with only two kana, the entire verb is treated as a suffix, and no dot is displayed, as it would appear before the word. For example:

• 要る い・る i.ru "need" – consonant stem ラ行五段
• 居る いる iru "be (animate)" – vowel stem ア行上一段

The terms "Group I", "Group II", and "Group III" are primarily used in Japanese language education, and may be notated as (I), (II), (III) next to a verb. Similarly, the terms "u verb" (う verb) and "ru verb" (る verb) are educational terms, and may be notated as （う） or （る）.

Verbs ending in iru and eru

General

Vowel stem verbs, such as ⾒る miru "to see" and 食べる taberu "to eat," end either in iru or eru (there are no other basic-form endings for this group), so most verbs ending in iru and eru are vowel stem verbs, but some consonant stem verbs have these endings, too, and there are also homophone verbs that have either a vowel stem or a consonant stem.

List of consonant stem verbs ending in iru

Verb	Kanji	English
aburagiru	脂ぎる	to be greasy
bibiru	びびる	to be surprised
chigiru	契る	to pledge
chiru	散る	to scatter
dojiru	どじる	to mess up
guchiru	愚痴る	to grumble
hairu	入る	to enter
hashiru	走る	to run
hiru	放る	to fart, to expel (from the body)
hojiru	穿る	to pick, dig out
hotobashiru	迸る	to gush, spurt
ibiru	いびる	to torment, roast
ijiru	弄る	to fiddle with
ikiru	熱る	to become sultry (note that ikiru (生きる) meaning "to live, to stay alive" is a vowel-stem verb)
iru	炒る	to boil down, to roast (note that iru (居る) meaning "to be" is a vowel-stem verb)
iru	入る	to go in (see iru above)
iru	要る	to need (see iru above)
kagiru	限る	to limit
kajiru	齧る	to gnaw
kashiru	呪る	to curse
kiru	霧る	to become misty (note that kiru (着る) meaning "to put on [clothing]" is a vowel-stem verb)
kiru	切る	to cut (see kiru above)
kishiru	きしる	to become misty
kishiru	軋る	to squeak, creak
kojiru	抉る	to gouge, wrench
kubiru	括る	to grip, strangle
kujiru	抉る	to gouge, scoop
mairu	参る	to come/go - humble
majiru	混じる	mingle
meiru	滅入る	to feel depressed
mikubiru	見縊る	to belittle; to despise
minagiru	漲る	to overflow
mogiru	捥る	to wrench
mojiru	捩る	to parody, to twist
mushiru	毟る	to pluck, to pick, to tear
najiru	詰る	to rebuke
nejiru	捩じる	to twist
nigiru	握る	to grasp
nijiru	躙る	to edge forward
nonoshiru	罵る	to abuse verbally
ochiiru	陥る	to fall, sink
omoiiru	思い入る	to ponder, to contemplate
omoikiru	思い切る	to dare to (usually in the form omoikitte (思い切って) or omoikitta (思い切った).)
sebiru	せびる	to pester for
shiru	知る	to know
soshiru	謗る	to slander
sujiru	捩る	to wriggle
tagiru	滾る	to boil, to seethe
tamagiru	魂消る	to be frightened
tobashiru	迸る	to gush
tochiru	とちる	to muff lines
yajiru	弥次る・野次る	to jeer at
yogiru	過る	to pass by, to drop in
yojiru	捩る	to twist, distort
yokogiru	横切る	to traverse

List of consonant stem verbs ending in eru

Verb	Kanji	English
aseru	焦る	to hurry
azakeru	嘲る	to ridicule
daberu	駄弁る	to chatter
eru	彫る	to carve (note that eru (得る) meaning "to get, to obtain" is a vowel-stem verb)
eru	選る	to choose (see eru above)
eru	啁る	to ridicule (see eru above)
fukeru	耽る	to be absorbed in
fuseru	臥せる	to hide, lie in ambush
haberu	侍る	to attend on
heru	減る	to decrease
hineru	捻る	to twist
hirugaeru	翻る	to turn over, to wave
hoteru	火照る	to flush, to feel hot
kaeru	反る・返る	to turn over (note that kaeru (変える) meaning "to alter" and kaeru (替える) meaning "to exchange" are vowel-stem verbs)
kaeru	返る・帰る・還る	to return (see kaeru above)
kaeru	孵る	to be hatched (see kaeru above)
kageru	陰る	to become dark, to be in shadow or shade
kakeru	駆ける	to run, to canter or gallop
keru	蹴る	to kick
kuneru	くねる	to be crooked
kutsugaeru	覆る	to be overturned
neru	練る	to temper, to refine, to knead (note that neru (寝る) meaning "to sleep" is a vowel-stem verb)
nomeru	のめる	to fall forward
numeru	滑る	to be slippery
omoneru	阿る	to flatter
seru	競る	to compete
seseru	挵る	to pick, play with
shaberu	喋る	to talk, to chat
shigeru	茂る	to grow thick
shikeru	湿気る	to become damp
soberu	そべる	to lie sprawled
suberu	滑る	to slip
takeru	猛る	to act violently
teru	照る	to shine
tsumeru	抓める	to pinch
tsuneru	抓る	to pinch
uneru	うねる	to undulate
yomigaeru	蘇る	to be brought back to life, to be refreshed

List of homophone verbs ending in iru that have both a vowel stem and a consonant stem

Verb	Vowel Stem	Consonant Stem
ikiru	生きる to live, to stay alive	熱る to become sultry
iru	居る to be	炒る to boil down, to roast 入る to go in 要る to need
kiru	着る to put on clothing	霧る to become misty 切る to cut

List of homophone verbs ending in eru that have both a vowel stem and a consonant stem

Verb	Vowel Stem	Consonant Stem
eru	得る to get, to obtain	彫る to carve 選る to choose 啁る to ridicule
heru	経る to pass (time/through)	減る to decrease
kaeru	変える to alter 替える to exchange	返る ・ 帰る ・ 還る to return 孵る to be hatched
neru	寝る to sleep	練る to temper, to refine, to knead
shimeru	閉める to close (something)	湿る to be damp

External links

• sci.lang.japan FAQ's list of iru and eru consonant-stem verbs.
• Aeron Buchanan's Japanese Verb Chart, a concise summary of all Japanese verbs conjugations on one sheet of A4

References

• Seiichi Makino and Michio Tsutsui, A dictionary of intermediate Japanese grammar, published by The Japan Times, ISBN 4-7890-0775-8.