Japanese Potential Form: How to Use Kanoukei (可能形)

The Japanese potential form, called kanoukei [可能形], is used to express what someone can do, what is possible, or what is available under certain conditions. If you have seen forms like 読める, 食べられる, or できる, you have already met it in real Japanese.

At first glance, the pattern looks simple: you change the dictionary form of a verb and the sentence starts carrying the meaning of “can” or “be able to.” In practice, however, learners often get confused by verb groups, the particles used with potential verbs, and the difference between forms like 見られる and 見える. This guide puts those points in order with natural examples you can reuse.

If you still need a broader foundation before focusing on potential verbs, it also helps to read our guide to Japanese verb forms, because the potential form becomes easier once you already recognize the main verb groups.

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What the potential form means in Japanese

In most cases, the potential form expresses ability, possibility, or opportunity. Depending on context, it can describe a learned skill, a temporary situation, or whether something is feasible at all.

• 日本語が読める。 I can read Japanese.
• 今日は早く来られない。 I cannot come early today.
• この図書館では日本語の本が借りられる。 You can borrow Japanese books at this library.

Notice that the nuance is not always the same as a direct English “can.” Sometimes it refers to personal ability, and sometimes it simply means that the situation allows the action.

How to conjugate godan verbs

With godan verbs, you change the final sound from the u-row to the e-row and then add る. This is why the potential form of 読む becomes 読める, and 話す becomes 話せる.

Dictionary form	Potential form	Meaning
読む	読める	can read
書く	書ける	can write
話す	話せる	can speak
待つ	待てる	can wait
泳ぐ	泳げる	can swim
買う	買える	can buy

A quick way to remember the pattern is to focus on the last kana. When the verb ends in む, it becomes める; when it ends in ぶ, it becomes べる; when it ends in く, it becomes ける, and so on.

How to conjugate ichidan and irregular verbs

With ichidan verbs, the standard pattern is easier: remove the final る and add られる.

• 食べる → 食べられる (can eat)
• 見る → 見られる (can see, can watch)
• 起きる → 起きられる (can wake up)
• 信じる → 信じられる (can believe)

In casual speech you may hear forms such as 食べれる or 見れる. They are common in conversation, but if you are studying standard written Japanese, it is better to master 食べられる and 見られる first.

The two main irregular verbs are short enough to memorize directly:

• する → できる
• 来る → 来られる (casual speech often also uses 来れる)

If irregular verb forms still trip you up, our article on irregular and uncommon Japanese verbs is a useful follow-up.

Using the potential form in real sentences

The potential form is more useful when you stop treating it as an isolated chart and start seeing how it behaves in natural sentences. Here are some common patterns:

Ability or skill

日本語が話せます。
I can speak Japanese.

Possibility created by the situation

この店では両替できます。
You can exchange money at this shop.

Negative potential

生の魚が食べられません。
I cannot eat raw fish.

Past potential

昨日は三時間しか寝られなかった。
Yesterday I could only sleep for three hours.

These patterns matter because the potential form is fully conjugatable. Once you know the base form, you can make it polite, negative, past, or combine it with other grammar points just like other Japanese verbs.

Should you use が or を?

This is one of the most common doubts. In learner-friendly grammar, the safest starting point is to use が with the thing that becomes possible:

日本語が読める。
肉が食べられる。

In real Japanese, you may also encounter sentences that keep を, especially in conversation. Even so, many textbooks and grammar references prefer が when teaching the potential form, and できる especially tends to pair naturally with が. If particles still feel unstable, our explanation of wa and ga with Japanese verbs helps clear up the logic.

Potential form or ことができる?

The structure ことができる often overlaps with the potential form. Both can mean “can do,” but they do not always feel equally natural.

• 日本語が話せる。 Natural and direct.
• 日本語を話すことができる。 More formal, more explicit, and often heavier in tone.

For everyday speech, the potential form is usually shorter and more fluid. ことができる appears more often in careful explanation, formal writing, or when the sentence structure benefits from sounding more deliberate.

見える and 聞こえる are not exactly the same thing

Learners often mix up the potential form with verbs such as 見える and 聞こえる. They are related in meaning, but they are not interchangeable in every sentence.

• 富士山が見える。 Mount Fuji is visible.
• 音が聞こえる。 I can hear the sound.
• 映画が見られる。 I can watch the movie.
• 先生の声が聞ける。 I can listen to the teacher's voice.

In other words, 見える and 聞こえる often describe what comes into your senses naturally, while 見られる and 聞ける are closer to ability or opportunity.

Common mistakes with kanoukei

One of the easiest mistakes is writing 可能系 instead of 可能形. The grammar term uses the kanji 形, which means “form.” Another common error is forcing the same rule onto every verb group, which leads to forms that sound unnatural or simply wrong.

It also helps to avoid memorizing potential conjugation as a sterile list. The fastest way to internalize it is to attach each form to a sentence you would actually say, such as talking about what you can eat, read, hear, watch, or understand.

Final thoughts

The Japanese potential form is one of the most useful verb patterns because it appears everywhere: in daily conversation, travel situations, class discussions, and study materials. Once you understand the difference between godan, ichidan, and irregular verbs, the pattern stops feeling random and starts becoming predictable.

If you want a simple practical routine, start by learning three things well: how to form 読める-type verbs, how to form 食べられる-type verbs, and when できる is the most natural option. From there, the rest of kanoukei becomes much easier to recognize and use.