Japanese Potential Form: How to Say Can and Cannot

The potential form is how Japanese says "can". 話せる (hanaseru) is "can speak". 行ける (ikeru) is "can go". It expresses ability, possibility, and — in casual speech — permission.

It is also the conjugation with the most collisions. The potential form looks like the passive for one whole verb group, and there are two different ways to say "can see" that mean different things. Both traps have clear answers once you see the shape of the problem.

How to build the potential form

The godan rule is the mirror image of the nai-form rule: the nai-form goes to the あ-row (書かない), the potential goes to the え-row (書ける). Same stem family, different vowel. If you have the nai-form automatic, the potential is one row over.

The result is a verb that ends in -eru, which means a potential form is itself an ichidan verb. 書ける conjugates as 書けます, 書けて, 書けない. That is convenient: once formed, nothing else special happens.

What it actually means

Three related senses, distinguished by context rather than by form.

Ability is about you; possibility is about circumstances; permission is about rules. Japanese uses one form for all three, which English does not — English has "can", "be able to", "may", "be allowed to". Do not assume a Japanese potential sentence is about personal skill. 明日行けます may mean "I have the free time tomorrow", not "I am capable of going".

If you need to be explicit about ability, 〜ことができる is clearer and slightly more formal.

The object takes が, not を

This is the change that catches everyone. In a potential sentence, the thing acted on is usually marked with が, not を.

The logic is that a potential sentence is less about doing something to an object and more about the object being available to you. 日本語が話せる (nihongo ga hanaseru) frames Japanese as the thing that is speakable.

The honest caveat: を is not impossible. In real Japanese, especially with verbs of motion and in longer sentences, を appears with potential forms — 日本語を話せる is heard, and この道を歩ける (kono michi o arukeru, "can walk this road") is normal because 歩く takes を for the path. Textbooks teach が as the rule, and it is the safe choice for a learner. Just do not be surprised when を shows up in native material.

する and 〜することができる

する has no regular potential. Its potential is できる (dekiru) — a completely different verb, and one of the most useful words in Japanese.

できる is also how you say you can do a noun-verb: 料理ができる (ryouri ga dekiru, "can cook"), 運転できる (unten dekiru, "can drive").

There is a second way to express potential that works for every verb: dictionary form + ことができます.

Same meaning, different register. The potential form is conversational and natural; 〜ことができます is formal and slightly wordy. In a self-introduction or a written report, 〜ことができます sounds careful and correct. Among friends, 泳げる is what people actually say. The structure is the verb nominalised with こと plus できる — see こと and の nominalisation.

The ら抜き split: 見れる versus 見られる

For ichidan verbs and 来る, the textbook potential (食べられる, 見られる, 来られる) is identical to the passive form. Speakers resolved that ambiguity by dropping the ら:

This is called ら抜き言葉 (ranuki kotoba, "ra-dropping speech"). Where it stands:

• In conversation it is normal. Most younger speakers use 見れる and 食べれる without thinking, and it removes a genuine ambiguity — 見れる is unambiguously "can see", while 見られる could be either.
• In formal writing it is still considered incorrect. Exams, business documents, and school essays expect 見られる.
• It only affects ichidan verbs and 来る. Godan verbs never had the problem, because their potential (書ける) and passive (書かれる) are already distinct. 書ける does not become 書れ. So the "rule" is not "drop ら from potentials" — it is "drop ら from the ichidan ones, where it causes a collision".

The practical advice: recognise both, use the full form in writing, and do not be surprised by either in speech. A learner who only knows 見られる will stumble on 見れる constantly in anime and conversation.

見える and 聞こえる are not potential forms

Japanese has a separate pair for perception, and they mean something different from the potential.

The distinction is about why. 見える and 聞こえる describe perception happening on its own — your eyes and ears work, and the thing is there. 見られる and 聞ける describe availability — you could watch it or listen to it if you wanted, because the conditions allow.

So 山が見える means the mountain is visible from here. 山が見られる would mean something like the mountain is open for viewing. English collapses both into "can see", which is exactly why the pair is worth learning deliberately.

Note also that 見える and 聞こえる are intransitive and stative — they take が, and they do not conjugate into a passive.

Verbs that have no potential form

A few common verbs do not take one, because they are already about a state rather than an action:

You will hear わかれる (wakareru) occasionally, but it usually means "can be divided" (from 分かれる, wakareru, a different verb) rather than "can understand". Treat わかる as having no potential form.

Negative potential, and "came to be able to"

Because a potential form is an ichidan verb, its negative is ordinary.

行けません is also the standard polite refusal in a shop or an office — それはできません (sore wa dekimasen, "that is not possible") is how Japanese says no without saying no directly.

To talk about acquiring an ability, Japanese does not use the potential form alone. It uses 〜ようになる (you ni naru), "to come to be that way":

The potential form states an ability; 〜ようになる reports the change. English blurs the two ("I can swim" / "I learned to swim"), which is why learners often say 泳げます when they mean 泳げるようになりました — technically true, but it loses the sense of progress.

Common mistakes for English speakers

Using られる as the godan potential. 行かれる (ikareru) is the passive — "to be gone to", or an adversity passive. The godan potential is 行ける (ikeru, "can go"). Because ichidan verbs use られる for both, English speakers over-apply it: 書かれる is "is written", never "can write".

Keeping を after the potential. 日本語を話せます is the classic slip. Use が: 日本語が話せます.

Trying to build する's potential by rule. しられる does not exist. する → できる.

Confusing 見える with 見られる. If the mountain is simply visible, it is 見える. 見られる is about permission or availability.

Assuming the potential form means personal ability. この店で買えます (kono mise de kaemasu) is about the shop, not about you — "you can buy it at this shop". Japanese potential sentences are often about circumstances, and reading them as statements about skill produces odd translations.

Mixing up the potential and passive in reading. For ichidan verbs both are られる and only context separates them. 先生に褒められる is "praised by the teacher" (passive, because of the に); 映画が見られる is "can watch the film". The particle before the verb is usually the giveaway — see passive and causative for the full contrast.

Assuming ら抜き is simply wrong. In conversation it is standard, and rejecting it outright makes real speech harder to follow. Learn both forms and know which register each belongs to.

Where to practise it

The potential form is where Japanese starts letting you talk about yourself — what you can do, what you cannot, what is possible tomorrow. That makes it one of the most rewarding conjugations to have automatic, and one of the most annoying to have half-learned, because the passive collision shows up in exactly the same shape.

The way through is volume: produce potential forms from real verbs until 書ける arrives before 書かれる does, and until 見られる versus 見れる stops being a decision.

Romaji.live practice has you type sentences like nihongo ga hanasemasu and eiga ga miraremasu from real Japanese, one word at a time, with the gloss shown when you get it right — which is how the が and the られる endings stop being things you have to think about. If the verb groups underneath are still shaky, start with verb classification; the closely related passive and causative is the natural next page.