The form to express "can do" with a verb has the following rules depending on the type of conjugation. For information on conjugation, see Verb.
Verbs that belong to Conjugation-aiueo (five-step conjugation)
Below are the conjugations for "話(はな)す (speak)". The grey background is not taken into account.
| Conjugation Form | Conjugation Ending | Conjugation | Pronunciation | English |
| 未然形 (みぜんけい) (imperfective form) | ～ない | 話(はな)さない | ha na sa na i | not speak |
| ～う or ～よう | 話(はな)そう | ha na so u | let's speak | |
| 連用形 (れんようけい) (conjunctive form) | ～ます | 話(はな)します | ha na shi ma su | speak (polite) |
| ～た | 話(はな)した | ha na shi ta | spoke | |
| 終止形 (しゅうしけい) (dictionary form) | 終止形 (しゅうしけい) (dictionary form) | 話(はな)す | ha na su | speak |
| 連体形 (れんたいけい) (attributive form) | ～とき or ～るとき | 話(はな)すとき | ha na su to ki | when speak |
| 仮定形 (かていけい) (conditional form) | ～ば or ～れば | 話(はな)せば | ha na se ba | if speak |
| 命令形 (めいれいけい) (imperative form) | 命令形 (めいれいけい) (imperative form) | 話(はな)せ | ha na se | speak (command) |
Regarding "話(はな)す (speak)" the conjugations of the expression "can do" are as shown in the table below.
| Conjugation Form | Conjugation Ending | Conjugation | Pronunciation | English |
| 未然形 (みぜんけい) (imperfective form) | ～ない | 話(はな)せない | ha na se na i | can not speak |
| ～う or ～よう | 話(はな)そう | ha na so u | let's speak | |
| 連用形 (れんようけい) (conjunctive form) | ～ます | 話(はな)せます | ha na se ma su | can speak (polite) |
| ～た | 話(はな)せた | ha na se ta | could speak | |
| 終止形 (しゅうしけい) (dictionary form) | 終止形 (しゅうしけい) (dictionary form) | 話(はな)せる | ha na se su | can speak |
| 連体形 (れんたいけい) (attributive form) | ～とき or ～るとき | 話(はな)せるとき | ha na se ru to ki | when can speak |
| 仮定形 (かていけい) (conditional form) | ～ば or ～れば | 話(はな)せれば | ha na se re ba | if can speak |
| 命令形 (めいれいけい) (imperative form) | 命令形 (めいれいけい) (imperative form) | 話(はな)せ | ha na se | speak (command) |
The conjugation is the same as Conjugation-e (lower one-step conjugation).
This is very important. Pay attention to the vowels. For verbs that belong to Conjugation-aiueo (five-step conjugation), when expressing "I can do ~", all the vowels are "え (e)".
| Conjugation Form | Conjugation | Pronunciation | English |
| 未然形 (みぜんけい) (imperfective form) | 話(はな)せない | ha na se na i | can not speak |
| 連用形 (れんようけい) (conjunctive form) | 話(はな)せます | ha na se ma su | can speak (polite) |
| 話(はな)せた | ha na se ta | could speak | |
| 終止形 (しゅうしけい) (dictionary form) | 話(はな)せる | ha na se su | can speak |
| 連体形 (れんたいけい) (attributive form) | 話(はな)せるとき | ha na se ru to ki | when can speak |
| 仮定形 (かていけい) (conditional form) | 話(はな)せれば | ha na se re ba | if can speak |
Extracts only vowels, as shown in the table below.
| Conjugation Form | Normal conjugation | can do ~ |
| 未然形 (みぜんけい) (imperfective form) | a (na i) | e (na i) |
| 連用形 (れんようけい) (conjunctive form) | i (ma su) | e (ma su) |
| i (ta) | e (ta) | |
| 終止形 (しゅうしけい) (dictionary form) | u | e (ru) |
| 連体形 (れんたいけい) (attributive form) | u (to ki) | e u (to ki) |
| 仮定形 (かていけい) (conditional form) | e (ba) | e e (ba) |
Verbs that belong to Conjugation-aiueo (five-step conjugation) often follow this rule.
Here are some other examples.
歩(ある)く (walk)
Normal conjugation
| Conjugation Form | Conjugation | Pronunciation | English |
| 未然形 (みぜんけい) (imperfective form) | 歩(ある)かない | a ru ka na i | not walk |
| 連用形 (れんようけい) (conjunctive form) | 歩(ある)きます | a ru ki ma su | walk (polite) |
| 歩(ある)いた | a ru i ta | walked | |
| 終止形 (しゅうしけい) (dictionary form) | 歩(ある)く | a ru ku | walk |
| 連体形 (れんたいけい) (attributive form) | 歩(ある)くとき | a ru ku to ki | when walk |
| 仮定形 (かていけい) (conditional form) | 歩(ある)けば | a ru ke ba | if walk |
can do ~
| Conjugation Form | Conjugation | Pronunciation | English |
| 未然形 (みぜんけい) (imperfective form) | 歩(ある)けない | a ru ke na i | can not walk |
| 連用形 (れんようけい) (conjunctive form) | 歩(ある)けます | a ru ke ma su | can walk (polite) |
| 歩(ある)けた | a ru ke ta | could walk | |
| 終止形 (しゅうしけい) (dictionary form) | 歩(ある)ける | a ru ke ru | can walk |
| 連体形 (れんたいけい) (attributive form) | 歩(ある)けるとき | a ru ke ru to ki | when can walk |
| 仮定形 (かていけい) (conditional form) | 歩(ある)ければ | a ru ke re ba | if can walk |
使(つか)う (use)
Normal conjugation
| Conjugation Form | Conjugation | Pronunciation | English |
| 未然形 (みぜんけい) (imperfective form) | 使(つか)わない | tsu ka wa na i | not use |
| 連用形 (れんようけい) (conjunctive form) | 使(つか)います | tsu ka i ma su | use (polite) |
| 使(つか)った | tsu ka tta | used | |
| 終止形 (しゅうしけい) (dictionary form) | 使(つか)う | tsu ka u | use |
| 連体形 (れんたいけい) (attributive form) | 使(つか)うとき | tsu ka u to ki | when use |
| 仮定形 (かていけい) (conditional form) | 使(つか)えば | tsu ka e ba | if use |
can do ~
| Conjugation Form | Conjugation | Pronunciation | English |
| 未然形 (みぜんけい) (imperfective form) | 使(つか)えない | tsu ka e na i | can not use |
| 連用形 (れんようけい) (conjunctive form) | 使(つか)えます | tsu ka e ma su | can use (polite) |
| 使(つか)えた | tsu ka e ta | could use | |
| 終止形 (しゅうしけい) (dictionary form) | 使(つか)える | tsu ka e ru | can use |
| 連体形 (れんたいけい) (attributive form) | 使(つか)えるとき | tsu ka e ru to ki | when can use |
| 仮定形 (かていけい) (conditional form) | 使(つか)えれば | tsu ka e re ba | if can use |
Conjugation-i (upper one-step conjugation)
Below are the conjugations for "見(み)る (see)". The grey background is not taken into account.
| Conjugation Form | Conjugation Ending | Conjugation | Pronunciation | English |
| 未然形 (みぜんけい) (imperfective form) | ～ない | 見(み)ない | mi na i | not see |
| ～う or ～よう | 見(み)よう | mi yo u | let's see | |
| 連用形 (れんようけい) (conjunctive form) | ～ます | 見(み)ます | mi ma su | see (polite) |
| ～た | 見(み)た | mi ta | saw | |
| 終止形 (しゅうしけい) (dictionary form) | 終止形 (しゅうしけい) (dictionary form) | 見(み)る | mi ru | see |
| 連体形 (れんたいけい) (attributive form) | ～とき or ～るとき | 見(み)るとき | mi ru to ki | when see |
| 仮定形 (かていけい) (conditional form) | ～ば or ～れば | 見(み)れば | mi re ba | if see |
| 命令形 (めいれいけい) (imperative form) | 命令形 (めいれいけい) (imperative form) | 見(み)ろ | mi ro | see (command) |
Regarding "見(み)る (see)" the conjugations of the expression "can do" are as shown in the table below.
| Conjugation Form | Conjugation Ending | Conjugation | Pronunciation | English |
| 未然形 (みぜんけい) (imperfective form) | ～ない | 見(み)られない | mi ra re na i | can not see |
| ～う or ～よう | 見(み)よう | mi yo u | let's see | |
| 連用形 (れんようけい) (conjunctive form) | ～ます | 見(み)られます | mi ra re ma su | can see (polite) |
| ～た | 見(み)られた | mi ra re ta | could see | |
| 終止形 (しゅうしけい) (dictionary form) | 終止形 (しゅうしけい) (dictionary form) | 見(み)られる | mi ra re ru | can see |
| 連体形 (れんたいけい) (attributive form) | ～とき or ～るとき | 見(み)られるとき | mi ra re ru to ki | when can see |
| 仮定形 (かていけい) (conditional form) | ～ば or ～れば | 見(み)られれば | mi ra re re ba | if can see |
| 命令形 (めいれいけい) (imperative form) | 命令形 (めいれいけい) (imperative form) | 見(み)ろ | mi ro | see (command) |
For verbs that belong to Conjugation-i (upper one-step conjugation), when expressing "can do", "られ" is inserted.
Conjugation-e (lower one-step conjugation)
Below are the conjugations for "寝(ね)る (sleep)". The grey background is not taken into account.
| Conjugation Form | Conjugation Ending | Conjugation | Pronunciation | English |
| 未然形 (みぜんけい) (imperfective form) | ～ない | 寝(ね)ない | ne na i | not sleep |
| ～う or ～よう | 寝(ね)よう | ne yo u | let's sleep | |
| 連用形 (れんようけい) (conjunctive form) | ～ます | 寝(ね)ます | ne ma su | sleep (polite) |
| ～た | 寝(ね)た | ne ta | slept | |
| 終止形 (しゅうしけい) (dictionary form) | 終止形 (しゅうしけい) (dictionary form) | 寝(ね)る | ne ru | sleep |
| 連体形 (れんたいけい) (attributive form) | ～とき or ～るとき | 寝(ね)るとき | ne ru to ki | when sleep |
| 仮定形 (かていけい) (conditional form) | ～ば or ～れば | 寝(ね)れば | ne re ba | if sleep |
| 命令形 (めいれいけい) (imperative form) | 命令形 (めいれいけい) (imperative form) | 寝(ね)ろ | ne ro | sleep (command) |
Regarding "寝(ね)る (sleep)" the conjugations of the expression "can do" are as shown in the table below.
| Conjugation Form | Conjugation Ending | Conjugation | Pronunciation | English |
| 未然形 (みぜんけい) (imperfective form) | ～ない | 寝(ね)られない | ne ra re na i | can not sleep |
| ～う or ～よう | 寝(ね)よう | ne yo u | let's sleep | |
| 連用形 (れんようけい) (conjunctive form) | ～ます | 寝(ね)られます | ne ra re ma su | can sleep (polite) |
| ～た | 寝(ね)られた | ne ra re ta | could sleep | |
| 終止形 (しゅうしけい) (dictionary form) | 終止形 (しゅうしけい) (dictionary form) | 寝(ね)られる | ne ra re ru | can sleep |
| 連体形 (れんたいけい) (attributive form) | ～とき or ～るとき | 寝(ね)られるとき | ne ra re ru to ki | when can sleep |
| 仮定形 (かていけい) (conditional form) | ～ば or ～れば | 寝(ね)られれば | ne ra re re ba | if can leep |
| 命令形 (めいれいけい) (imperative form) | 命令形 (めいれいけい) (imperative form) | 寝(ね)ろ | ne ro | sleep (command) |
For verbs that belong to Conjugation-e (lower one-step conjugation), when expressing "can do", "られ" is inserted. It is the same as Conjugation-i (upper one-step conjugation).
Conjugation-kuru (irregular conjugation of the ka-row)
Below are the conjugations for "来(く)る (come)". The grey background is not taken into account.
| Conjugation Form | Conjugation Ending | Conjugation | Pronunciation | English |
| 未然形 (みぜんけい) (imperfective form) | ～ない | 来(こ)ない | ko na i | not come |
| ～う or ～よう | 来(こ)よう | ko yo u | let's come | |
| 連用形 (れんようけい) (conjunctive form) | ～ます | 来(き)ます | ki ma su | come (polite) |
| ～た | 来(き)た | ki ta | came | |
| 終止形 (しゅうしけい) (dictionary form) | 終止形 (しゅうしけい) (dictionary form) | 来(く)る | ku ru | come |
| 連体形 (れんたいけい) (attributive form) | ～とき or ～るとき | 来(く)るとき | ku ru to ki | when come |
| 仮定形 (かていけい) (conditional form) | ～ば or ～れば | 来(く)れば | ku re ba | if come |
| 命令形 (めいれいけい) (imperative form) | 命令形 (めいれいけい) (imperative form) | 来(こ)い | ko i | come (command) |
Regarding "来(く)る (come)" the conjugations of the expression "can do" are as shown in the table below.
| Conjugation Form | Conjugation Ending | Conjugation | Pronunciation | English |
| 未然形 (みぜんけい) (imperfective form) | ～ない | 来(こ)られない | ko ra re na i | can not come |
| ～う or ～よう | 来(こ)よう | ko yo u | let's come | |
| 連用形 (れんようけい) (conjunctive form) | ～ます | 来(こ)られます | ko ra re ma su | can come (polite) |
| ～た | 来(こ)られた | ko ra re ta | could come | |
| 終止形 (しゅうしけい) (dictionary form) | 終止形 (しゅうしけい) (dictionary form) | 来(こ)られる | ko ra re ru | can come |
| 連体形 (れんたいけい) (attributive form) | ～とき or ～るとき | 来(こ)られるとき | ko ra re ru to ki | when can come |
| 仮定形 (かていけい) (conditional form) | ～ば or ～れば | 来(こ)られれば | ko ra re re ba | if can come |
| 命令形 (めいれいけい) (imperative form) | 命令形 (めいれいけい) (imperative form) | 来(こ)い | ko i | come (command) |
The only verb that belongs to Conjugation-kuru (irregular conjugation of the ka-row) is "来(く)る (come)". I recommend you to memorize it.
Conjugation-suru (irregular conjugation of the sa-row))
Below are the conjugations for "する (do)". The grey background is not taken into account.
| Conjugation Form | Conjugation Ending | Conjugation | Pronunciation | English |
| 未然形 (みぜんけい) (imperfective form) | ～ない | しない | shi na i | not do |
| ～う or ～よう | しよう | shi yo u | let's do | |
| 連用形 (れんようけい) (conjunctive form) | ～ます | します | shi ma su | do (polite) |
| ～た | した | shi ta | did | |
| 終止形 (しゅうしけい) (dictionary form) | 終止形 (しゅうしけい) (dictionary form) | する | su ru | do |
| 連体形 (れんたいけい) (attributive form) | ～とき or ～るとき | するとき | su ru to ki | when do |
| 仮定形 (かていけい) (conditional form) | ～ば or ～れば | すれば | su re ba | if do |
| 命令形 (めいれいけい) (imperative form) | 命令形 (めいれいけい) (imperative form) | しろ | shi ro | do (command) |
Regarding "する (do)" the conjugations of the expression "can do" are as shown in the table below.
| Conjugation Form | Conjugation Ending | Conjugation | Pronunciation | English |
| 未然形 (みぜんけい) (imperfective form) | ～ない | できない | de ki na i | can not do |
| ～う or ～よう | しよう | shi yo u | let's do | |
| 連用形 (れんようけい) (conjunctive form) | ～ます | できます | de ki ma su | can do (polite) |
| ～た | できた | de ki ta | could do | |
| 終止形 (しゅうしけい) (dictionary form) | 終止形 (しゅうしけい) (dictionary form) | できる | de ki ru | can do |
| 連体形 (れんたいけい) (attributive form) | ～とき or ～るとき | できるとき | de ki ru to ki | when can do |
| 仮定形 (かていけい) (conditional form) | ～ば or ～れば | できれば | de ki re ba | if can do |
| 命令形 (めいれいけい) (imperative form) | 命令形 (めいれいけい) (imperative form) | しろ | shi ro | do (command) |
The only verb that belongs to Conjugation-suru (irregular conjugation of the sa-row) are "する (do)" and "～する (do ~)". I recommend you to memorize it.
Summary
Here's a quick summary:
- The only verb that belongs to Conjugation-kuru (irregular conjugation of the ka-row) is "来(く)る (come)". There's only one, so I recommend you to memorize it.
- Verbs that belong to Conjugation-suru (irregular conjugation of the sa-row) are "する (do)" "勉強(べんきょう)する (study)" "仕事(しごと)する (work)" an so on. For example, "勉強(べんきょう)する" is "勉強(べんきょう) + する", so you just need to put the conjugated form of "する" after "勉強(べんきょう)". In other words, you only need to memorize the conjugations of "する".
- There are few verbs that belong to Conjugation-i (upper one-step conjugation). If you are a beginner in Japanese, you should start by learning only the following verbs.
- 起(お)きる (wake up)
- 着(き)る (put on)
- 過(す)ぎる (pass)
- 落(お)ちる (fall)
- 見(み)る (see)
- 降(お)りる (get off)
- There are also few verbs that belong to Conjugation-e (lower one-step conjugation). If you are a beginner in Japanese, you should start by learning only the following verbs.
- 受(う)ける (take e.g. take examination)
- 見(み)せる (show)
- 混(ま)ぜる (mix)
- 捨(す)てる (throw away)
- 茹(ゆ)でる (boil)
- 出(で)る (go out and other mianings)
- 寝(ね)る (sleep)
- 食(た)べる (eat)
- 入(い)れる (put in)