Potential Form可能形
The potential form expresses ability: "can do," "be able to." Japanese builds this directly into the verb conjugation rather than using a separate helper word. For godan verbs, shift to the え-row and add -ru. For ichidan verbs, add -rareru (or colloquially -reru). する becomes できる, and 来る becomes 来られる.
The potential form expresses ability: "can do," "be able to." Japanese builds this directly into the verb conjugation rather than using a separate helper word. For godan verbs, shift to the え-row and add -ru. For ichidan verbs, add -rareru (or colloquially -reru). する becomes できる, and 来る becomes 来られる.
How to form the potential
The rules differ by group.
Godan: え-row + る
Change the final kana to the え-row equivalent and add る: 書く→書ける (kakeru), 話す→話せる (hanaseru), 読む→読める (yomeru), 買う→買える (kaeru), 泳ぐ→泳げる (oyogeru). The result is an ichidan verb, so further conjugation follows ichidan rules: 書ける→書けない→書けた→書けます.
Ichidan: stem + られる (or れる)
Formally, add -rareru: 食べる→食べられる (taberareru), 見る→見られる (mirareru). In casual modern Japanese, many speakers drop the ら: 食べれる, 見れる. This is called ら抜き言葉 (ra-nuki kotoba). Textbooks and formal writing require the full -rareru, but you’ll hear -reru constantly in daily speech.
Irregular
する→できる (dekiru). This is a completely different word, not a conjugation. 来る→来られる (korareru), or casually 来れる (koreru).
The を→が particle shift
In potential sentences, the object particle often shifts from を to が: 日本語を話す → 日本語が話せる. This happens because the potential form focuses on the subject’s ability rather than the action on the object. Both を and が are used in modern Japanese, but が is traditional and preferred in formal writing. In casual speech, を is increasingly common and accepted.
The ら抜き debate
ら抜き言葉 (dropping ら from -rareru) is one of the most debated topics in Japanese linguistics. Against ら抜き: purists, textbooks, NHK, and formal writing reject it as "incorrect." For ら抜き: it removes ambiguity (食べられる could be potential OR passive, but 食べれる is unambiguously potential), and over 80% of speakers under 40 use it naturally. As a learner, know both forms. Use -rareru in formal contexts and JLPT tests. Use -reru casually if you want to sound natural among friends.
できる and ことができる
できる (the potential of する) means "can do" and works as a standalone verb: 料理ができる (can cook). For verbs that aren’t する-compounds, use dictionary form + ことができる as an alternative to the potential form: 日本語を話すことができる = 日本語が話せる. ことができる is more formal and commonly used in written Japanese.
Nuances of ability
The potential form covers both learned ability (ピアノが弾ける = I can play piano) and situational possibility (今日は早く帰れる = I can go home early today). For pure situational possibility, Japanese also uses ～られる or ～うる/える: そういうことも起こりうる (Such things can happen). The potential form is the default choice for everyday "can" statements.
Potential form conjugation
| Verb | Group | Potential | Potential negative | Potential polite |
|---|---|---|---|---|
| 書く | Godan | 書ける | 書けない | 書けます |
| 話す | Godan | 話せる | 話せない | 話せます |
| 読む | Godan | 読める | 読めない | 読めます |
| 泳ぐ | Godan | 泳げる | 泳げない | 泳げます |
| 買う | Godan | 買える | 買えない | 買えます |
| 食べる | Ichidan | 食べられる | 食べられない | 食べられます |
| 見る | Ichidan | 見られる | 見られない | 見られます |
| 起きる | Ichidan | 起きられる | 起きられない | 起きられます |
| する | Irreg. | できる | できない | できます |
| 来る | Irreg. | 来られる (korareru) | 来られない | 来られます |
Example sentences
漢字が500個読める。
Kanji ga gohyakko yomeru.
I can read 500 kanji.
Godan potential + が particle
お箸で食べられますか。
Ohashi de taberaremasu ka.
Can you eat with chopsticks?
Ichidan potential (formal -rareru)
明日のパーティーに来れる？
Ashita no paatii ni koreru?
Can you come to tomorrow’s party?
ら抜き casual: 来られる→来れる
この問題は誰にもできない。
Kono mondai wa dare ni mo dekinai.
Nobody can solve this problem.
できる (potential of する) negative
日本語で冗談が言えるようになりたい。
Nihongo de joudan ga ieru you ni naritai.
I want to become able to tell jokes in Japanese.
～ようになる = to become able to
一人で全部食べれるの？
Hitori de zenbu tabereru no?
You can eat all of it by yourself?
ら抜き casual: 食べられる→食べれる
Common mistakes
日本語を話すことができます (when speaking casually)
日本語が話せるよ
ことができる is formal/written. In casual speech, use the potential form directly: 話せる. ことができる in conversation sounds stiff.
見える for "can watch" (intentional)
見られる / 見れる for "can watch"
見える means "is visible" (natural ability, no effort). 見られる means "can watch/look at" (intentional). 富士山が見える (Fuji is visible) vs この映画は見られる (I can watch this movie).
聞こえる for "can listen to"
聞ける for "can listen to"
Same as 見える/見られる: 聞こえる = "is audible" (passive). 聞ける = "can listen" (active choice). 音楽が聞こえる (I can hear music) vs この曲が聞ける (I can listen to this song).
食べられる on JLPT when you mean passive
Context determines meaning
食べられる can mean "can eat" (potential) OR "is eaten" (passive). This ambiguity is exactly why ら抜き (食べれる) exists — it eliminates confusion by making 食べれる unambiguously potential.
Frequently asked questions
Should I use ら抜き (食べれる) or the full form (食べられる)?
Both are correct in modern Japanese. Use 食べられる in formal writing, business Japanese, and JLPT exams. Use 食べれる in casual conversation with friends — it’s how most native speakers actually talk. Learning both is essential.
What’s the difference between potential form and ことができる?
They mean the same thing, but ことができる is more formal and common in written Japanese, speeches, and official contexts. The potential form (話せる, 読める) is more natural in spoken Japanese. Don’t use ことができる in casual conversation — it sounds like you’re reading from a textbook.
Why does する become できる instead of following a pattern?
Historically, できる (出来る) was a separate verb meaning "to come out / to be produced." Over time, it absorbed the meaning of "can do" and became the de facto potential of する. This is a true suppletive form (like English "go" → "went"), not a regular conjugation.
What is the potential of 書く?
書く → ?