Japanese/Grammar/Verbs

Japanese verbs, ( 動詞; どうし ), inflect heavily to indicate formality, tense or mood, primarily in their ending. There are two tenses, several levels of formality and three classes of verbs, depending on their inflection. The two tenses are perfective (often considered past tense) and present (or technically, non-past, as the future tense is not indicated). Out of the several levels of formality, two are the most common: plain and polite.

Japanese verbs are officially categorised into five classes, but as two of these inflect much the same and another two only contain one verb each, these are usually merged into three when Japanese is taught as a foreign language. These are the consonant stem-, vowel stem- and irregular classes.

Dictionaries use the plain present positive form (commonly known as dictionary form) as the headword for verbs.

Verbs are classed based on their conjugations. Their endings don't determine the class, but are a general indicator.

Different inflections can also have suffixes. These may also be verbs with their own conjugations. Not all suffixes can be used on all verb inflections and others may only follow the verb stem. Examples are conjunctive + いる, せる ・ させる (causative), and られる (potential).

Ignoring the formality and the negative conjugations, the following is a list of verb conjugations
 * non-past
 * past
 * causative
 * causative-passive
 * conjunctive
 * conditionals
 * passive
 * potential
 * imperative
 * volitional
 * provisional

Ichidan class
Vowel-stem verbs end on a full syllable (hence the term: vowel-stem). In a sense, the final " る " of the dictionary form is dropped and the respective endings just added on.

The Japanese term " " refers to the fact that the stem ending occupies only one row in the kana chart.

The following table shows a few forms of the verb " 食べる " ( たべる, e. to eat):

Godan class
Consonant-stem verbs end in the middle of a syllable (hence the term; consonant-verb). That syllable changes depending on the form. The plain form has an う u sound ( u , ts u , r u , k u , g u , b u , m u , s u ), the ～ます -masu form has an い i sound ( i , ch i , r i , k i , g i , b i , m i , sh i ), and the negative form has an あ a sound (w a , t a , r a , k a , g a , b a , m a , s a ). The potential form has an え e sound ( e , t e , r e , k e , g e , b e , m e , s e ) and the volitional form has an おう ō sound ( ō , t ō , r ō , k ō , g ō , b ō , m ō , s ō ), so putting these together with the sounds above shows that verb conjugations follow the vowel syllabary of the Japanese character set:　あ a, い i, う u, え e and お o.

The Japanese term "" comes from the fact that the stem's last syllable spans all five rows of the kana chart in at least one form.

The following table shows a few forms of the consonant-stem verb "話す" (はなす e. to speak).

The て-form (conjunctive) and past positive form of a consonant-stem verb change the root for euphony according to the last syllable of the root (example in parentheses):

行く (いく) (to go) has an exceptional て-form 行って (いって).

If the verb stem ends on "う" such as in the verb 買う(かう, e. to buy) then its negative stem becomes -わ as in 買わない ("to not buy"). This is because the root is treated as kawu (despite the "wu" syllable not existing in modern Japanese).

Irregular verbs
Two common verbs do not share a conjugation pattern with any other verb. They are therefore commonly classed as "irregular" verbs. Formally, they are called "変格" (へんかく) verbs, as opposed to the regular "正格" (せいかく) verbs. This construction is made to use verbs and nouns of Chinese origin, for instance, from Chinese "確認"　(què rèn, confirmation) is formed in Japanese the verb " 確認する " (かくにんする), or "約分" (yuē fēn, simplify a fraction (math.)) which derives into "約分する"　(やくぶんする). The forms are "する" (e. to do, as in the examples) and "" (e. to come). The following table shows some of their conjugation forms.

Many verbs end on "〜する" and can be grouped in three categories:
 * Verbalised nouns. These are nouns which form verbs by appending "〜する". Examples:, , ", and.
 * Verbs that cannot stand alone without the "する" suffix. Examples:, and.
 * Verbs that cannot stand alone, end on an "ん" and therefore take the voiced "ずる". Examples:, , and . These verbs are commonly inflected the same as the ichidan forms, with "ずる" being replaced by "じる" thus: , ,  and.

The only commonly-used combination with "来る" is "やってくる", meaning "to come".

Polite forms
The polite (or formal) forms are simple as all of the consonant-stem verbs sit in the い-line (行く→行き) and the inflections are the same for consonant- and vowel-stem verbs.

The following table shows the polite forms for "行く" (いく, e. to go):

The imperative (〜ませ) is not used in formal forms except for a few polite verbs (see below).

Other irregularities
A small number of verbs tend to be conjugated differently from the groups that they are normally placed in.

Polite language
The verbs below are all consonant stem verbs but conjugate differently. While the regular forms also exist, they are seldom used.

The conjunctive and past forms of the first two verbs, "くださる" and "なさる", also have the alternative forms "くだすって／くだすった" and "なすって／なすった", in addition to the normal regular conjugations "くださって／くださった" and "なさって／なさった". These alternative forms have, however, fallen into disuse. While they are often encountered when reading texts from a few decades ago, the regular conjugations are usually used today.

The first three of the above verbs are also the only ones where the imperative form "ませ" of the auxiliary verb, "ます", is used to add an extra level of politeness:

Additionally, ございます, which originally came from the now-defunct yodan (四段, e. four-row) classical Japanese verb "ござる", is also used, although in modern usage, it is always used with the ます auxiliary verb ending. There is no imperative form (i.e. you cannot use ませ like above).

得る
得る (うる/える, e. to get, or to be able to) is the only surviving nidan (二段, e. two-row) class verb in modern Japanese. It has conjugations as in the below table:

"得る" can be read both as "える" in its terminal form (at the end of the sentence, or in situations such as attaching to べき). The "うる" reading is also used in those situations and in the attributive form (e.g. when attached to nouns). It is therefore incorrect to say "えるもの" as the correct form would be "うるもの". The combination "あり得る" is normally read "ありうる" in the present forms. All other conjugations follow the table above.

Miscellaneous irregularities
The vowel stem verb "呉れる" (くれる e. ) imperative form "くれ" (rather than the expected "くれろ"). Other "くれる" verbs of other unrelated meanings conjugate to the usual "くれろ".

The consonant stem verb "ある" expresses existence, but absence is expressed with the adjective "ない". Note that many textbooks also treat "ない" as a verb. The reader may also wish to be aware that more formal "ぬ" negative form and its conjunctive form, "ず", are still used: "あらぬ"/"あらず".

Summary of verb conjugations
See the adjective inflection Wikipedia page for present negative, past and past negative forms of i and na adjectives.