Can' & 'Cannot' in Japanese – Expressing Ability & Limits

 Being able to express ability and limitations is essential in any language. In Japanese, "can" and "cannot" are conveyed using specific verb conjugations and expressions. This guide will walk you through how to properly use these forms.

Can' & 'Cannot' in Japanese

1. Using the Potential Form of Verbs

The potential form of a verb is used to express ability, meaning that someone can or is able to do something. Each verb group has a different method of conjugation.

Conjugation Rules:

Group 1 (Godan) Verbs

For Godan (五段) verbs, change the final "-u" sound to "-eru."

Verb	Potential Form	Meaning
書く (kaku)	書ける (kakeru)	can write
行く (iku)	行ける (ikeru)	can go
話す (hanasu)	話せる (hanaseru)	can speak
読む (yomu)	読める (yomeru)	can read

Group 2 (Ichidan) Verbs

For Ichidan (一段) verbs, replace "-ru" with "-rareru."

Verb	Potential Form	Meaning
食べる (taberu)	食べられる (taberareru)	can eat
見る (miru)	見られる (mirareru)	can see

Irregular Verbs

There are two irregular verbs that follow different rules:

Verb	Potential Form	Meaning
する (suru)	できる (dekiru)	can do
来る (kuru)	来られる (korareru)	can come

Example Sentences:

✅ 日本語を話せます。 (Nihongo o hanasemasu.) – I can speak Japanese.
✅ 漢字が読める。 (Kanji ga yomeru.) – I can read kanji.

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2. Saying "Cannot" in Japanese

To express "cannot", you need to conjugate the verb into its negative potential form:

Conjugation Rules for Negative Potential Form:

Group 1 (Godan) Verbs

Change "-eru" to "-enai."

Verb	Potential Negative Form	Meaning
書ける (kakeru)	書けない (kakenai)	cannot write
行ける (ikeru)	行けない (ikenai)	cannot go

Group 2 (Ichidan) Verbs

Change "-rareru" to "-rarenai."

Verb	Potential Negative Form	Meaning
食べられる (taberareru)	食べられない (taberarenai)	cannot eat
見られる (mirareru)	見られない (mirarenai)	cannot see

Irregular Verbs

Verb	Potential Negative Form	Meaning
できる (dekiru)	できない (dekinai)	cannot do
来られる (korareru)	来られない (korarenai)	cannot come

Example Sentences:

✅ お酒が飲めません。 (Osake ga nomemasen.) – I cannot drink alcohol.
✅ 今日は学校に行けない。 (Kyō wa gakkō ni ikenai.) – I cannot go to school today.

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3. Alternative Ways to Express Ability and Limitation

Using ことができる (koto ga dekiru)

A more formal way to say "can" or "cannot" is by using ことができる (koto ga dekiru).

✅ ピアノを弾くことができます。 (Piano o hiku koto ga dekimasu.) – I can play the piano.
✅ 泳ぐことができません。 (Oyogu koto ga dekimasen.) – I cannot swim.

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4. Expressing Restrictions and Physical Limitations

Using ～てはいけない (~te wa ikenai)

To express "must not" or "not allowed," use ～てはいけない.

✅ ここで写真を撮ってはいけません。 (Koko de shashin o totte wa ikemasen.) – You cannot take photos here.

Using ～が下手 (ga heta) or ～が苦手 (ga nigate)

To indicate difficulty or lack of skill, use:

• 下手 (heta) – bad at something

• 苦手 (nigate) – weak at something

✅ 私は歌が下手です。 (Watashi wa uta ga heta desu.) – I am bad at singing.
✅ 彼は泳ぐのが苦手です。 (Kare wa oyogu no ga nigate desu.) – He is not good at swimming.

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5. FAQs About "Can" and "Cannot" in Japanese

1. What is the difference between ～ことができる and the potential form?

ことができる is more formal and used in writing, while the potential form is more natural in speech.

2. Can I use できる with all verbs?

No. できる is mainly used with nouns or the する verb (e.g., 勉強する → 勉強できる – can study).

3. How do I say "I can’t" in a casual way?

Use the negative potential form, e.g., 行けない (ikenai) – I can’t go.

4. Is the potential form polite?

Yes, when used with ます (e.g., 食べられます), it becomes polite. Without ます, it is casual.

5. How do I say "not allowed" instead of "cannot"?

Use ～てはいけません, e.g., タバコを吸ってはいけません – Smoking is not allowed.

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By mastering the potential form, ことができる, and alternative expressions, you can confidently talk about your abilities and limitations in Japanese. Keep practicing and incorporating these forms into your daily conversations!