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 (godan, u-verb)	hashir.u ("run") 走る (godan, u-verb, -iru verb)	mi.ru ("see") 見る (kami ichidan, ru-verb, -iru verb)	tabe.ru ("eat") 食べる (shimo ichidan, ru-verb, -eru verb)
Negative	yom.anai 読ま-ない	hashi.nai 走-ない	mi.nai 見-ない	tabe.nai 食べ-ない
Polite form	yom.imasu 読み-ます	hashi.masu 走-ます	mi.masu 見-ます	tabe.masu 食べ-ます
Potential form	yom.eru 読め-る	hashi.reru 走-れる	mi.(ra)reru 見-(ら)れる¹ ²	tabe.(ra)reru 食べ-(ら)れる¹
Volitional form	yom.ou 読も-う	hashi.rou 走-ろう	mi.you 見-よう	tabe.you 食べ-よう

1. Note that colloquially the ら ra is dropped meaning these two become 見れる mireru and 食べれる 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 have also irregular potential forms are ik.eru/ik.areru ("can go") and kik.eru/kik.oeru ("can hear"). Other irregular potential forms 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), but some consonant-stem verbs have these endings, too (e.g. 散る chiru "to scatter," 抓める tsumeru "to pinch"), and there are also "homophone verbs" that have either a vowel stem or a consonant stem (e.g. ikiru vowel 生きる "to live, to stay alive," consonant 熱る "to become sultry"; shimeru vowel 閉める "to close [something]," consonant 湿る "to be damp").

Rules of thumb

• There are more consonant verbs than vowel verbs.
• All verbs not ending in -iru/-eru are consonant-stem verbs; this includes -aru/-uru/-oru verbs and verbs with a vowel ending in the basic form, such as 買う kau "to buy" and 言う iu "to say."
• Over half of verbs ending in -iru has a consonant stem (e.g., of the 419 -iru verbs listed in EDICT, 248 [ca. 60%] have a consonant stem), and the majority of verbs ending in -eru has a vowel stem (e.g., of the 3013 -eru verbs listed in EDICT, 2886 [ca. 95%] have a vowel stem).
• If the vowel i/e of the ending -iru/-eru is part of a kanji (as in 契る chigi-ru "to pledge" and 嘲る azake-ru "to ridicule"), as opposed to being part of an okurigana, chances are high that the verb has a consonant stem.
  • However, this rule is not applicable for two-syllable verbs (⾒る mi-ru, for example, has a vowel stem) and verbs written only in hiragana (for example, びびる bibiru "to be surprised" and のめる nomeru "to fall forward" have consonant stems). Some consonant-stem verbs also have the syllable with the ending vowel written in hiragana, e.g. 混じる ma-jiru "to mingle" and the mentioned-above verb 抓める tsu-meru "to pinch."
  • -eru verbs having the e sound written in hiragana listed in EDICT: 2934 (ca. 97% of -eru verbs listed there, of them 2901 vowel verbs and 33 consonant verbs)
  • -eru verbs having the e sound in a kanji listed in EDICT: 139 (of them 39 vowel verbs and 100 consonant verbs).

Examples of conjugation

The "homophone verbs" iru (vowel: いる (居る) to be [animated] ; consonant: 炒る to boil down, to roast, 入る to go in, 要る to need) and eru (vowel: 得る to get, to obtain; consonant: 彫る to carve, 選る to choose, 啁る to ridicule):

	Vowel stem (-iru)	Consonant stem (-iru)	Vowel stem (-eru)	Consonant stem (-eru)
Plain form	i.ru	ir.u	e.ru	er.u
Negative	i.nai	ir.anai	e.nai	er.anai
Polite form	i.masu	ir.imasu	e.masu	er.imasu
Potential form 1	i.rareru	ir.eru	e.rareru	er.eru
Volitional form	i.you	ir.ou	e.you	er.ou

¹ Potential forms of consonant verbs are conjugated like vowel verbs: ireru / ereru → iremasu / eremasu, etc. The same is true for passive forms (irareru / erareru → iraremasu / eraremasu, etc.). In vowel verbs, potential and passive forms are identical (irareru / erareru).

Rule of thumb: In vowel verbs, the basic-ending -ru is completely replaced by the new ending (e.g. iru / eru → inai / enai), while in consonant verbs, the -r sound is kept and followed by another vowel, to which the new ending is added (e.g. iru / eru → iranai / eranai). However, in the -te/-ta forms, consonant verbs drop the -r sound and replace it by -tte/-tta (e.g. itte, itta / ette, etta), while vowel verbs have -te/-ta (e.g. ite, ita / ete, eta).

Lists of verbs (examples)

The following lists are not complete; feel free to add other verbs.

Homophone vowel-stem and consonant-stem verbs ending in -iru

Verb	Vowel stem	Consonant stem
chibiru	禿びる to get blunt, to dull, to wear out	ちびる 1. to wet oneself, to shit oneself 2. to be miserly
hiru	干る to dry 嚏る to sneeze	放る to expel (from the body)
ikiru	生きる to live, to stay alive	熱る to become sultry
iru	射る to shoot 居る to be (animated) 鋳る・鑄る to cast, to mint, to coin 癒る to calm down	煎る・炒る・熬る to boil down, to roast 入る to go in 要る to need 沒る・没る to set beyond the Western horizon (i.e. the sun)
kiru	着る・著る to put on clothing	霧る to become misty 斬る to kill someone with a blade 切る to cut 剪る to cut, to prune, to trim (plants) 截る to cut (e.g. cloth) 伐る to cut down (e.g. trees) 鑽る・鑚る to start a fire (with wood-wood friction or by striking metal against stone)
komiiru	込み居る to push in, to be crowded	込み入る・込入る to push in, to be crowded, to be complicated

Homophone vowel-stem and consonant-stem verbs ending in -eru

Verb	Vowel stem	Consonant stem
eru	得る・獲る to get, obtain	彫る・雕る・鐫る to carve 選る・択る to choose 啁る to ridicule
fukeru	更ける・深ける to get late, to advance, to wear on 蒸ける to become ready to eat (as a result of steaming) 老ける・化ける to age, to grow old ふける to run away (e.g. from work)	耽る・耽ける 1. to indulge in, to give oneself up to, to be obsessed by 2. to be engrossed in, to be lost in, to be absorbed in
furikaeru	振り替える・振りかえる・振替える to change (e.g. a bill), to transfer (e.g. money), to switch over, to move over	振り返る・振りかえる・ふり返る・振返る to turn head, to look over one's shoulder, to turn around, to look back
fuseru	伏せる 1. to bend down, to bow down 3. to hide oneself	臥せる to lie down, to retire, to go to bed
heru	経る・歴る to pass (time/through)	減る to decrease
hineru	陳ねる to age	捻る・拈る・撚る 1. to twist, to wrench, to turn (off/on), to wring (a neck) 2. to puzzle over 3. to defeat easily
kaeru	変える to change, to alter 換える・替える・代える to exchange	帰る・還る・歸る to return 返る・反る to return 孵る to hatch out
kakeru	掛ける・懸ける1. to hang (e.g. picture), to hoist (e.g. sail), to raise (e.g. flag) 2. to sit 3. to be partway (verb), to begin (but not complete) 4. to take (time, money), to expend (money, time, etc.) 5. to make (a call) 6. to multiply 7. to secure (e.g. lock) 8. to put on (glasses, etc.) 9. to cover 10. to burden someone 11. to apply (insurance) 12. to turn on (an engine, etc.), to set (a dial, an alarm clock, etc.) 13. to put an effect (spell, anaesthetic, etc.) on 14. to hold an emotion for (pity, hope, etc.) 15. to bind 16. to pour (or sprinkle, spray, etc.) onto 17. to argue (in court), to deliberate (in a meeting), to present (e.g. idea to a conference, etc.) 18. to increase further 19. to catch (in a trap, etc.) 20. to set atop 21. to erect (a makeshift building) 22. to hold (a play, festival, etc.) 23. (after -masu stem of verb) indicates (verb) is being directed to (someone) 駆ける・駈ける 1. to run (race, esp. horse), to dash 2. to gallop (one's horse), to canter 3. to advance (against one's enemy) 4. to soar, to fly 5. to run, to dash 欠ける・缺ける・闕ける 1. to be chipped, to be damaged, to be broken 2. to be lacking, to be missing 3. to be insufficient, to be short, to be deficient, to be negligent toward 4. (of the moon) to wane, to go into eclipse 賭ける to wager, to bet, to risk, to stake, to gamble 架ける to suspend between two points, to build (a bridge, etc.), to put up on something (e.g. legs up on table)	翔る・駆ける・翔ける 1. to soar, to fly 2. to run, to dash
michikaeru	持ち替える・持替える・持ち換える to change way one holds something (esp. transferring it from one hand to the other)	持ち帰る・持帰る to bring back, to carry home, to take out (e.g. food)
mikaeru	見変える・見替える to forsake one thing for another	見返る to look back
nameru	舐める・嘗める,甞める 1. to lick 2. to taste 3. to experience (esp. a hardship) 4. to make fun of, to trer with contempt	滑る to be slippery, to be slimy
neru	寝る・寐る to sleep	練る・煉るto temper, to refine, to knead
okikaeru	置き換える・置き替える to replace, to move, to change the position of	起き返る to rise, to erect, to get up
shimeru	閉める to close (something)	湿る to be damp
suberu	統べる・総べる to control, to supervise	滑る・辷る 1. to glide, to slide 2. to fail 3. to drop, to go/come down, to fall (e.g. in status)
takeru	炊ける to be boiled/cooked/ready 長ける・闌ける 1. to excel at, to be proficient 2. to grow old 3. to ripen 4. to rise high (e.g. the sun)	猛る 1. to rage, to be fierce 2. to be excited 哮る to roar, to howl

Consonant-stem verbs ending in -iru

Note: Homophone verbs listed above are not repeated here.

Verb	Kanji and/or hiragana	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
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
kagiru	限る	to limit
kajiru	齧る	to gnaw
kashiru	呪る	to curse
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	to 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

Consonant-stem verbs ending in -eru

Note: Homophone verbs listed above are not repeated here.

Verb	Kanji and/or hiragana	English
aseru	焦る	to be in a hurry
azakeru	嘲る	to ridicule
daberu	駄弁る	to chatter
haberu	侍る	to attend on
hirugaeru	翻る	to turn over, to wave
hoteru	火照る	to flush, to feel hot
kageru	陰る	to become dark, to be in shadow or shade
keru	蹴る	to kick
kuneru	くねる	to be crooked
kutsugaeru	覆る	to be overturned
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
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

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.