This section deals only with Japanese as written and spoken in 21st and late 20th centuries.
There are two major types of conjugation: in Japanese "school grammar" they are called godan katsuyō (五段活用) and ichidan katsuyō (一段活用). They are also called constant-stem and vowel-stem, u-verb and ru-verb, and some textbooks use Group I and Group II. The main difference is that in the dictionary (lemma) form, godan verbs can end in any -u sound while ichidan verbs can only end with ru. In addition, ichidan katsuyō is further divided into kami ichidan katsuyō (上一段活用) and shimo ichidan katsuyō (下一段活用) based on whether they end in -iru or -eru (no other vowel before the ru is possible). That said, if a regular verb in its dictionary form ends in -iru or -eru, it will be ichidan in most cases. In all other cases it is godan.
Modern Japanese has mainly two irregular verbs: 来る and する. Some textbooks categorize the two as well as derivatives of the latter (旅行する, ジョギングする) as Group III. In school grammar they also have their own categories: カ行変格活用 and サ行変格活用. In addition, irregular conjugation also occurs in Japanese honorific speech as well as a small number of words derived from する (like 愛する).
- godan verbs: change the -u to -a (but -wa if it has no consonant) and attach -nai. For example, 読む becomes 読まない.
- ichidan verbs: drop the -ru and attach -nai. For example, 見る becomes 見ない.
- irregular verbs: kuru becomes konai, suru becomes shinai.
Once a verb reaches negative form, it can be further inflected like an -i adjective. For example, negative past is negative form with なかった instead. Sometimes ぬ, ず, or ん is attached instead of ない-based endings.
The past form of a verb is formed by attaching た to its 連用形. However, there are several kinds of euphonic changes (音便), and some change the attached た to its voiced version だ. Therefore some textbook lists the past form (as well as the similar te-form) as a separate conjugation itself. The all-in-one rules are as follows:
- godan verbs: if the final kana is く, ぐ, one of ぶ／む／ぬ, one of つ／る／う, or す, they're changed to いた, いだ, んだ, った, and した, respectively. For example, 読む becomes 読んだ. (Occasionally exceptions might apply, such as 行く→行った, 問う→問うた.)
- ichidan verbs: drop the -ru and attach -ta. For example, 見る becomes 見た.
- irregular verbs: kuru becomes kita, suru becomes shita.
The 連用形 of a verb is also called its stem or continuative form.
- godan verbs: change the -u to -i. For example, 読む becomes 読み.
- ichidan verbs: simply drop the -ru. For example, 見る becomes 見.
- irregular verbs: kuru becomes ki, suru becomes shi.
The 連用形 is sometimes used to turn the verb into a noun (yasumu means to take a rest while yasumi means holiday, absence, etc.) and make compound words (like 読みやすい, 読み方, 読み返す). It is also useful in certain kinds of expressions: 読みます (polite form of 読む), 読みたい (want to read), 読みながら (while reading), 読みな(さい) (please read!), 読みそう (seem to read),
Conjunctive or te formEdit
- godan verbs: if the final kana is く, ぐ, one of ぶ／む／ぬ, one of つ／る／う, or す, they're changed to いて, いで, んで, って, and して respectively. For example, 読む becomes 読んで. (Occasionally exceptions might apply, such as 行く→行って, 問う→問うて.)
- ichidan verbs: drop the -ru and attach -te. For example, 見る becomes 見て.
- irregular verbs: kuru becomes kite, suru becomes shite.
A series of events can be expressed by conjugating all but the last verb to their te form (or in formal writing to the 連用形):
- Toshokan ni itte, benkyō o shita. Sorekara ie e kaette shukudai o shita.
- Went to library and studied. After that went home and did homework. (Only the last verb in each sentence conjugate according to the tense.)
The form is also useful in certain kinds of expressions: 読んでから (after reading), 読んでも(いい) (even if read (it's ok)), 読んではだめ/いけない/ならない (it's not ok to read), 読んで下さい (please read), 読んでいる (in the state of reading), 読んである (have been read, lit. been read and exists), 読んでばかり (is always reading), 読んであげる (help others read), 読んでくれる (help me/us read), 読んでもらう (receive the favor of reading), 読んでおく (read in preparation, for example for a test), 読んでしまう (read completely or by accident), 読んでみる (try reading), etc. When followed by いく (from 行く) or くる (from 来る) as a set expression, the basic meaning is to do something towards a direction (帰る is "return", 帰っていく is "go back", while 帰ってくる is "come back") and the notion of the direction can be abstract (towards the future, up to the present, come to the state, etc.) Also, if a sentence ends with a verb in the te form, it's probably a contraction of ～て下さい and is a request:
- godan verbs: change the -u to -e. For example, 読む becomes 読め.
- ichidan verbs: change the -ru to -ro. For example, 見る becomes 見ろ.
- irregular verbs: kuru becomes koi, suru becomes shiro.
The volitional form carries the meaning of "let's do something" and in the polite form of verbs, this is done by changing the ます to ましょう. For dictionary (lemma) forms of verbs it has the same meaning when used alone and means "try to do" when followed by とする. It also means "I want to do something", but a less direct way to say this is to follow it by と思う. The conjugation is:
- godan verbs: change the -u to -ō. For example, 読む becomes 読もう.
- ichidan verbs: change the -ru to -yō. For example, 見る becomes 見よう.
- irregular verbs: kuru becomes koyō, suru becomes shiyō.
Hypothetical conditional formEdit
One of way to say "if" is to attach ば to the 仮定形 of a verb, which is formed by changing the final vowel u (whether in -u, -ru, kuru, suru) to an e. "AばB" implies that A is a condition for B to happen.
- godan verbs: change the -u to -eru. For example, 読む becomes 読める.
- ichidan verbs: change the -ru to -rareru. For example, 見る becomes 見られる.
- irregular verbs: kuru becomes korareru, suru becomes dekiru.
- godan verbs: change the -u to -a (but -wa if it has no consonant) and attach seru. For example, 読む becomes 読ませる.
- ichidan verbs: change the -ru to -saseru. For example, 見る becomes 見させる.
- irregular verbs: kuru becomes kosaseru, suru becomes saseru.
The result can be further conjugated like an ichidan verb. Sometimes the せる is abbreviated as a single す and conjugates as godan verbs. The object is usually introduced with を, but when there is another object with を (such as "A made B sing a song"), に is used instead.
- godan verbs: change the -u to -a (but -wa if it has no consonant) and attach reru. For example, 読む becomes 読まれる.
- ichidan verbs: change the -ru to -rareru. For example, 見る becomes 見られる.
- irregular verbs: kuru becomes korareru, suru becomes sareru.
The result can be further conjugated like an ichidan verb. Aside from the passive voice (where the performer of the verb is introduced with に or によって), the form is also used to show politeness in which case the sentence structure does not change. In casual speech, the せる can be abbreviated as a single す and conjugates as godan verbs. The passive form is sometimes used for a victimhood state, for example, 兎に逃げられた is not "was run away by the rabbit", but "rabbit ran away, resulting in loss".
These are the basic forms of verbs as taught in Japan. Verbs have six associated stem forms; three of these each appear in two different ways that are not given separate names, but are used in disjoint contexts. The izenkei (已然形, classical perfective form) is also called the kateikei (仮定形, hypothetical form in modern Japanese). The shūshikei (終止形, terminal form) and rentaikei (連体形, attributive form) are identical for verbs in modern Japanese.
|Passive 受動態||1, kuru||imperfective (general)||られる||shimo-1 verb||食べられる|
|5||imperfective (general)||れる||shimo-1 verb||書かれる|
|Causative 使役態||1, kuru||imperfective (general)||させる or さす||shimo-1 verb||食べさせる|
|5||imperfective (general)||せる or す||shimo-1 verb||書かせる|
|suru||irreg.||irreg.||shimo-1 verb||させる or さす|
|Potential 可能法||1||imperfective (general)||られる||shimo-1 verb||食べられる|
|5, kuru, 1 (colloq.)||classical imperfective||る||shimo-1 verb||書ける, 起きれる|
|suru||defective||defective||出来る (せる in compounds)|
|Volitional||1, kuru, suru||imperfective (volitional)||よう||indeclinable||食べよう, こよう, しよう|
|5||imperfective (volitional)||う||indeclinable||書こう, 話そう|
|Negative||all||imperfective (general)||ない||i-adjective||食べない, 書かない, こない, しない|
|Negative (archaic)||all||imperfective (general)||ぬ||indeclinable||食べぬ, 書かぬ|
|Negative Continuative (-zu)||1, 5, kuru||imperfective (general)||ず||indeclinable||食べず, 書かず, こず|
|Negative Conjunctive (-naide)||all||imperfective (general)||ないで||indeclinable||起きないで, 書かないで, こないで, しないで|
|Past tense||1, kuru, suru, (ka,sa,ta,ra,wa)-5||continuative (other)||た||indeclinable||食べた, きた, した, 書いた, 行った, 話した, 待った, 作った, 払った, 問った|
|(ga,na,ba,ma)-5||continuative (other)||だ||indeclinable||泳いだ, 死んだ, 読んだ, 飲んだ|
|Conjunctive (-te)||1, kuru, suru, (ka,sa,ta,ra,wa)-5||continuative (other)||て||indeclinable||食べて, きて, して, 書いて, 行って, 話して, 待って, 作って, 払って, 問って|
|(ga,na,ba,ma)-5||continuative (other)||で||indeclinable||泳いで, 死んで, 読んで, 飲んで|
|Hypothetical (-ba)||all||classical imperfective (hypothetical)||ば||indeclinable||起きれば, 書けば, くれば, すれば|
|Conditional (-tara)||1, kuru, suru, (ka,sa,ta,ra,wa)-5||continuative (other)||たら||indeclinable||食べたら, きたら, したら, 書いたら|
|(ga,na,ba,ma)-5||continuative (other)||だら||indeclinable||泳いだら, 死んだら, 読んだら, 飲んだら|
Suffixes to the continuative (-i) formEdit
There are several suffixes that attach to the continuative (-i) form. These are some of the most common:
|Formal (-masu)||ます||irregular verb||行きます|