This is the single-shape reference for the potential form（可能形, かのうけい）— the "can / be able to" of Japanese. There is one anchor to memorize, 書く→書ける（かける, "can write"）, and everything else is a variation on it: a 五段 verb walks its final kana to the え-row and adds る, a 一段 verb adds られる, and the two irregulars go their own suppletive way — する becomes できる, 来る becomes 来られる（こられる）. Two things trip everyone up, and both get their own section below: the object particle usually flips を→が, and casual speech drops the ら from the 一段 form (食べれる).
The core split: え-row+る vs +られる
Everything hinges on the class. A 五段 verb already has five vowel rows to walk across, and the potential lives on the え-row, with る glued on:
- 書く（ka-ku）→ 書ける（ka-ke-ru）
- 話す（hana-su）→ 話せる（hana-se-ru）
- 飲む（no-mu）→ 飲める（no-me-ru）
A 一段 verb has no rows to walk — its stem is a rock — so it just takes the full られる:
- 食べる → 食べられる
- 見る → 見られる
私はギターは弾けるけど、ピアノは弾けない。
watashi wa gitā wa hikeru kedo, piano wa hikenai
I can play the guitar, but I can't play the piano.
この漢字、読める？
kono kanji, yomeru?
Can you read this kanji?
辛すぎて、半分しか食べられなかった。
karasugite, hanbun shika taberarenakatta
It was too spicy — I could only eat half.
The full table
| Class | Dictionary | Potential | Reading | Rule |
|---|---|---|---|---|
| 五段 -く | 書く | 書ける | kakeru | え-row + る |
| 五段 -す | 話す | 話せる | hanaseru | え-row + る |
| 五段 -む | 飲む | 飲める | nomeru | え-row + る |
| 五段 -る | 取る | 取れる | toreru | え-row + る |
| 五段 -う | 買う | 買える | kaeru | え-row + る（う→え, no わ） |
| 一段 | 食べる | 食べられる | taberareru | stem + られる |
| 一段 | 見る | 見られる | mirareru | stem + られる |
| する (irregular) | する | できる | dekiru | suppletive |
| 来る (irregular) | 来る | 来られる | korareru | こ + られる |
Note the -う row: unlike the passive and causative (which insert わ — 買われる, 買わせる), the potential lands on the え-row, so 買う simply becomes 買え + る = 買える. No わ. See the passive table for the わ-insertion that does happen there.
Potential verbs are themselves 一段
Whatever class you started from, the potential you produce conjugates as a 一段 verb — drop る, add the ending, no sound changes:
| Form | 書ける | Reading |
|---|---|---|
| Plain negative | 書けない | kakenai |
| Polite | 書けます | kakemasu |
| Past | 書けた | kaketa |
| te-form | 書けて | kakete |
This is why できる (the する potential) inflects できない・できます・できた — it is a plain 一段 verb too.
予約すれば、週末でも泊まれますよ。
yoyaku sureba, shūmatsu demo tomaremasu yo
If you book ahead, you can stay even on weekends.
すみません、明日は行けそうにないです。
sumimasen, ashita wa ikesō ni nai desu
Sorry — it doesn't look like I'll be able to make it tomorrow.
The object flips を→が
This is the pitfall that catches every English speaker. When you make a verb potential, its direct object typically stops being marked with を and takes が instead, because the sentence has shifted from "I do X" to "X is do-able (for me)" — a statement about capacity, not action.
私はスペイン語が少しできます。
watashi wa supeingo ga sukoshi dekimasu
I can speak a little Spanish.
この水、そのまま飲めますか？
kono mizu, sonomama nomemasu ka?
Can you drink this water straight from the tap?
The textbook-standard and exam-safe choice is が（日本語が話せる）. In real speech を is widely heard — especially when other words sit between the object and the verb — and is increasingly accepted. But できる is strict: it is a fully intransitive stative verb and takes only が (料理ができる, never ×料理を…). For the deeper account of when を creeps back in, see を vs が with the potential and 〜たい.
The irregulars: できる and 来られる
する does not build a potential from its own stem — there is no ×せられる in modern usage. It is replaced wholesale by the standalone verb できる（出来る）. 来る is regular-ish: the こ-stem takes られる, giving 来られる（こられる）.
パーティー、土曜なら来られる？
pātī, doyō nara korareru?
Can you come to the party if it's on Saturday?
もう自分でボタンが留められるようになったね。
mō jibun de botan ga tomerareru yō ni natta ne
You can do up your own buttons now, can't you.
The ら抜き shortcut: 食べれる
Modern spoken Japanese trims the 一段 potential from 食べられる → 食べれる（食べれる, tabereru）— dropping the ら. This is ら抜き言葉, and it does one genuinely useful thing: it splits the potential off from the identical-looking passive and honorific (all three of which share 食べられる). 食べれる can only mean "can eat."
今夜はこの辺で流れ星が見られるらしいよ。
kon'ya wa kono hen de nagareboshi ga mirareru rashii yo
Apparently you can catch shooting stars around here tonight.
この魚、生でも食べれるって。
kono sakana, nama demo tabereru tte
They say you can eat this fish raw.
The catch is register: 食べれる, 見れる, 来れる are unremarkable in conversation and texting, but still counted nonstandard in essays, exams, and business writing — where you write the full 食べられる, 見られる, 来られる. The full breakdown of which verbs allow it is on the ら抜き potential table.
Three meanings, one shape (一段 only)
Because a 一段 potential is 食べられる, it is spelled identically to the passive and the honorific. 五段 verbs never have this problem — their potential (書ける) looks nothing like their passive (書かれる). The full disambiguation lives on passive vs potential vs honorific; for now, remember that for 一段 verbs, context alone tells "can eat," "gets eaten," and "(a respected person) eats" apart.
Common mistakes
❌ 私は日本語が話せられる。
watashi wa nihongo ga hanaserareru
Incorrect — 話す already becomes 話せる on the え-row. Adding られる double-marks the potential. This is the number-one error: applying the 一段 られる to a 五段 verb.
✅ 私は日本語が話せる。
watashi wa nihongo ga hanaseru
I can speak Japanese.
❌ 私は料理ができられる。
watashi wa ryōri ga dekirareru
Incorrect — the する potential is the suppletive できる. There is no ×できられる and no ×せられる.
✅ 私は料理ができる。
watashi wa ryōri ga dekiru
I can cook.
❌ 私はお酒をたくさん飲めます。
watashi wa o-sake o takusan nomemasu
Nonstandard — the potential prefers が on its object. English 'I can drink a lot' pushes you toward を, but standard and exam Japanese wants が.
✅ 私はお酒がたくさん飲めます。
watashi wa o-sake ga takusan nomemasu
I can drink a lot of alcohol.
❌ ここから海が見られる。
koko kara umi ga mirareru
Wrong verb for 'the sea is visible.' Passive visibility that just happens to your eyes is 見える (spontaneous); 見られる means you get the opportunity to view something.
✅ ここから海が見える。
koko kara umi ga mieru
You can see the sea from here.
❌ 明日は会議に来れます。
ashita wa kaigi ni koremasu
Register error in formal writing — 来れる is ら抜き (casual). In a business email use the full form.
✅ 明日は会議に来られます。
ashita wa kaigi ni koraremasu
I can come to the meeting tomorrow. (formal)
Key takeaways
- 書ける is the anchor. 五段 = final kana to the え-row + る; 一段 = stem + られる; する→できる; 来る→来られる（こられる）.
- The -う row lands on the え-row (買える), with no わ — unlike the passive/causative.
- Every potential is a 一段 verb: 書ける→書けない・書けます・書けた.
- The object usually flips を→が (日本語が話せる); できる takes only が.
- ら抜き 食べれる means only "can eat" and is fine in speech, nonstandard in formal writing.
- For 一段 verbs, potential = passive = honorific in shape (食べられる) — 五段 verbs are spared this because their potential is the separate 書ける.
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Start learning Japanese→Related Topics
- Passive 受身: Formation TableN4 — The one-shape reference for the passive: 五段 walk to the あ-row and add れる (書く→書かれる), 一段 add られる (食べられる), する→される, 来る→来られる — with the わ-insertion trap and the three-meanings-one-shape collision on 一段 verbs.
- できる: The Suppletive Potential of するN4 — できる is a regular 一段 verb that serves as the suppletive potential of する — 'can do' — and also means 'be completed / come into being'; the potential of する is never ×される or ×せられる.
- ら抜き言葉: Potential Without らN3 — The reference for the colloquial ら抜き potential — where 一段 verbs and 来る drop the ら of られる (食べれる, 見れる, 来れる), why 五段 verbs are untouched, and the one thing ら抜き actually does better than the full form.