Potential Form (可能形) — How to Express Ability

Meaning & Usage

The potential form (可能形, かのうけい) expresses what someone can do, is able to do, or what is possible in a given situation. English uses the modal verb "can" for this — Japanese builds the meaning directly into the verb through conjugation. Expect to encounter this form constantly: in conversation, on signs, in restaurant menus, and in formal writing.

Think of it as adding a capability layer to an action verb. 食たべる means "to eat," but 食たべられる means "can eat." Same action, but the potential form asks whether that action is within reach. It covers two distinct situations:

• Personal ability: Describing what a person can or cannot do based on skill, physical ability, or circumstance. For example, "I can speak Japanese" or "She can't swim."
• Situational possibility: Describing whether something is possible or available in a given situation. For example, "You can take photos here" (it is permitted or possible) or "You can see cherry blossoms in spring" (they are available to be seen).

One important nuance: with potential verbs, the object often takes が instead of を. The focus shifts from the action to the state of being capable — 日本語にほんごを話はなす (speak Japanese, action) becomes 日本語にほんごが話はなせる (can speak Japanese, ability). Modern usage accepts を as well, so you'll encounter both. For the JLPT, が is the safer choice.

Group 2 potential forms are visually identical to passive forms. 食たべられる can mean "can eat" or "is eaten" depending on context. When no agent is marked with に, it tends to be potential; when an agent appears with に (e.g., 猫ねこに食たべられる — eaten by the cat), it is passive. Particles and context together resolve the ambiguity.

Formal speech always uses the full forms — 食たべられる, 見みられる. In casual Japanese, ら-抜ぬき言葉ことば (ra-nuki kotoba) trims that ら: 食たべれる, 見みれる. You'll hear these constantly in everyday speech, but they're non-standard on the JLPT and in formal writing.

Structure & Formation

The potential form is built differently depending on the verb group. Japanese verbs fall into three categories: Group 1 (u-verbs / 五段動詞ごだんどうし), Group 2 (ru-verbs / 一段動詞いちだんどうし), and two irregular verbs. Getting the group right is what everything else hinges on.

Group 1 — う動詞どうし：Change the final -u sound to -eru

Group 2 — る動詞どうし：Replace final -る with -られる

不規則動詞ふきそくどうし — Irregular Verbs

Once formed, the potential verb conjugates as a Group 2 verb. For example: 書かける → 書かけます (polite) → 書かけない (plain negative) → 書かけました (polite past) → 書かけなかった (plain negative past).

The ことができる structure is a formal equivalent, common in written Japanese:

日本語にほんごが話はなせる ＝ 日本語にほんごを話はなすことができる (I can speak Japanese)

Example Sentences

Basic Personal Ability

Situational Possibility

Skills and Talents

Using できる for Ability

Natural and Seasonal Possibility

Common Mistakes

Mistake 1: Using する's potential form incorrectly

❌ 料理りょうりをしられます。

✅ 料理りょうりができます。

する is completely irregular — its potential form is できる, not しられる or しれる. Those forms don't exist in standard Japanese. For any noun-based activity, use Noun + が + できる: 料理りょうりができる (can cook), 運転うんてんができる (can drive), 水泳すいえいができる (can swim).

Mistake 2: Dropping ら in formal writing

❌ （公式こうしきな文書ぶんしょで）明日あした来これます。

✅ （公式こうしきな文書ぶんしょで）明日あした来こられます。

ら-抜ぬき言葉ことば is fine in casual speech, but formal writing, business emails, and the JLPT all require the full ら. If casual speech has trained you to drop it, make a conscious switch when the context is formal.

Mistake 3: Confusing potential and passive voice

❌ 先生せんせいは生徒せいとに褒ほめられました。(Thinking this means: "The teacher could praise the student")

✅ This sentence actually means: "The teacher was praised by the student." (passive, not potential)

For Group 2 verbs and irregular くる, potential and passive forms look identical — 食たべられる, こられる. Look for a に-marked agent: if someone is performing the action upon another party, it's passive. Without that agent, it's typically potential. Parsing the particles carefully is what separates the two.

Mistake 4: Wrong structure with ことができる

❌ 私わたしは泳およぐができます。

✅ 私わたしは泳およぐことができます。

こと must sit between the plain dictionary form and できる. こと nominalizes the verb — turning the action into a noun concept — which then acts as the subject of できる. Drop こと and the sentence breaks. The pattern is: [辞書形じしょけい] + こと + が + できる.

Mistake 5: Applying Group 1 rules to Group 2 verbs

❌ 食たべれます。（正式せいしきな場面ばめんで）

✅ 食たべられます。

Mixing up Group 1 and Group 2 rules is a common slip at this stage. Group 2 verbs need -られる, not -れる. 食たべれる exists as colloquial ら-抜ぬき言葉ことば, but 食たべれます in polite speech sounds off and flags a gap in formal grammar. Drill the distinction until choosing the right form is instinctive.

Cultural Notes

The potential form does more than state facts — it smooths over uncomfortable situations. Declining an invitation is a prime example. 行いきません (I won't go) sounds blunt in Japanese; 行いけません (I can't go) is softer and less confrontational, even when the real reason is simply not wanting to go. Japanese communication leans toward indirectness, and the negative potential form is one of its most reliable tools for that.

You'll find this pattern across professional and social contexts alike. At work: 今日は対応たいおうできません (I can't handle this today) instead of a flat refusal. Among friends: 今日きょうはちょっと来こられなくて (I kind of can't make it today) as a gentle bow-out. Start using this and your Japanese will feel noticeably less foreign.

Signs, menus, and public announcements also rely on the potential form to describe what's available or permitted. A museum might post ここで写真しゃしんが撮とれます (Photos can be taken here) or 写真しゃしんは撮とれません (No photography). In these cases the nuance is situational — permission or availability, not personal skill.

Linguists have tracked ら-抜ぬき言葉ことば for decades — what was once labeled a grammatical error is now understood as a natural shift in spoken Japanese. Young speakers use 見みれる, 食たべれる, and これる freely in casual conversation. You'll hear them constantly in dramas and everyday speech, but stick to the standard form in formal writing and on the JLPT.

Related Grammar Points

• Imperative Form — Commanding and Ordering (Grammar N3)
• ことができる — Can Do, Be Able To (Grammar N5)
• Japanese Passive Voice (Grammar N3)
• ことにしている — Make It A Rule To / I Always Make Sure To (Grammar N3)
• Volitional Form (意向形): Expressing Intention, Invitation, and Attempt (Grammar N3)
• ざるを得ない — Have No Choice But (Grammar N3)

JLPT Tips

The potential form appears on both JLPT N4 and N3. N3 goes beyond basic conjugation — expect questions on particle choice (が vs を), potential-vs-passive disambiguation, and ことができる equivalence. Know all three verb groups cold before the exam.

Particle questions are a recurring trap. が is the traditional and preferred choice with potential verbs, though modern usage accepts を too. When the exam offers が vs を with a potential verb, pick が.

Watch for the potential vs. passive ambiguity with Group 2 verbs — exam questions frequently exploit this overlap. Scan immediately for a に-marked agent: if someone or something is performing the action on another party, it's passive. No agent, and the subject has the ability? Potential.

Always write the standard form on the JLPT — no ら-抜ぬき言葉ことば. 見みれる and これる are fine in conversation, but the exam expects 見みられる and こられる. The ことができる structure also appears regularly in grammar equivalence questions, so practice converting between the two forms until it's automatic.

Speed matters too. Instant recall of 飲のむ → 飲のめる, 起おきる → 起おきられる, and する → できる frees up mental bandwidth for the harder questions in the grammar section.