ことができる — Can Do, Be Able To

Meaning & Usage

ことができる expresses ability — the idea that someone can do something, or that something is possible. It maps cleanly to English "can" or "be able to," and shows up constantly at the N5 level.

The pattern has three moving parts. こと (koto) nominalizes a verb — turning "eat" into "the act of eating." が (ga) marks that noun phrase as the subject. できる (dekiru) means "to be possible." Strung together, 食たべることができる literally reads as "the act of eating is possible" — which in practice just means "can eat."

ことができる leans formal. In casual conversation, most Japanese speakers reach for the shorter potential verb form — 食たべられる instead of 食たべることができる. Written Japanese is a different story: business emails, official announcements, and JLPT passages all favor ことができる. Learning both lets you read native material accurately and match the right register.

ことができる describes standing ability or general possibility — a skill you have, or something that is permitted. It doesn't fit one-off lucky outcomes. Use it to say you can speak Japanese as a skill, not to describe stumbling across something by accident.

One rule holds without exception: ことができる always takes the dictionary form of the verb before こと. Never the て-form, た-form, or any other conjugation. Once you internalize that rule, the pattern is completely predictable.

Structure & Formation

Take any verb in dictionary form, attach こと, then が, then できる. No exceptions.

To make the negative form (cannot do), change できる to できない (plain negative) or できません (polite negative):

• 食たべることができない — cannot eat (casual)
• 食たべることができません — cannot eat (polite)

To make the past tense (was able to / could), change できる to できた (plain past) or できました (polite past):

• 泳およぐことができた — was able to swim (casual)
• 泳およぐことができました — was able to swim (polite)

Example Sentences

Basic Ability

Negative — Cannot Do

Past Tense — Was Able To

Questions — Can You...?

Expressing What Is Possible

Common Mistakes

Mistake 1: Using the wrong verb form before こと

❌ 食たべてことができます。

✅ 食たべることができます。

Always use the dictionary form before こと. The て-form connects clauses or makes requests — it has no place in this pattern.

Mistake 2: Dropping が after こと

❌ 泳およぐことできます。

✅ 泳およぐことができます。

が between こと and できる is required. こと turns the verb phrase into a noun, and が marks that noun as the subject of できる. You might hear が dropped in very casual spoken Japanese, but it remains a grammar error in standard usage.

Mistake 3: Confusing こと with の in this pattern

❌ 話はなすのができます。

✅ 話はなすことができます。

の can nominalize verbs in Japanese, but のができる is not standard for expressing ability. Stick with こと here. の does appear with other patterns — のが上手 (good at doing), のが好き (like doing) — but when the verb is できる, こと is the right choice.

Mistake 4: Using ことができる for instant / accidental results

❌ ころんで、偶然ぐうぜん答こたえを見みつけることができた。

✅ ころんで、偶然ぐうぜん答こたえを見みつけた。

ことができる describes general ability or deliberate possibility. For one-time or accidental outcomes, drop ことができる and use the plain past tense instead.

Mistake 5: Forgetting to use polite できません for formal negatives

❌ (会議かいぎで) 参加さんかすることができない。

✅ (会議かいぎで) 参加さんかすることができません。

In any formal or professional context — meetings, emails, speaking to a teacher or client — use the polite negative できません, not できない. Japanese register rules are strict; a casual form in the wrong setting can undermine the entire interaction.

Cultural Notes

In Japanese workplace culture, ことができる is the go-to phrasing on résumés, in business emails, and in official notices. A job applicant listing language skills might write 「英語えいごを話はなすことができます」 — that formal construction carries weight that the casual 話はなせる simply doesn't.

Among friends, the shorter potential verb form is the default. 「食たべられる」 flows naturally in conversation; 「食たべることができる」 can sound stiff in the same context. Both are grammatically correct — knowing which to reach for is a matter of reading the room.

Signs and public notices in Japan rely heavily on ことができます. You will see 「ここで駐車ちゅうしゃすることができます」(You can park here) and 「この区間くかんでは飲食いんしょくすることができません」(No eating or drinking in this section) everywhere from trains to museums. Spot this pattern and you can decode most rules-and-permissions signage without a dictionary.

Japanese culture values modesty about personal ability. When asked whether you can do something, a softened answer is often more appreciated than a confident yes. 「少すこしだけ話はなすことができます」(I can speak just a little) sounds appropriately humble — even when your Japanese is actually quite good.

Related Grammar Points

• たことがある — Have Done Before (Grammar N5)
• か — Question Marker (Grammar N5)
• ながら — While Doing Two Things at Once (Grammar N5)
• が (Conjunction) — But, However (Formal Contrast) (Grammar N5)
• てください — Please Do (Grammar N5)
• ましょう — Let's Do Something Together (Volitional Polite) (Grammar N5)

JLPT Tips

ことができる comes up in both the N5 grammar section and reading passages. Expect to identify it, complete sentences using it, and understand it in context.

A frequent question type asks you to pick the correct particle to complete a sentence. The particle between こと and できる is always が — never は, を, or に. If you see 「話はなすこと___できます」, the answer is が, every time.

Questions also test the correct verb form before こと. It is always dictionary form. Drill these high-frequency verbs until they're automatic: 食たべる, 飲のむ, 書かく, 読よむ, 来くる, する, 行いく, 見みる, 聞きく, 話はなす.

Reading passages often set scenes in museums, parks, or restaurants — exactly the contexts where ことができます thrives. Train yourself to spot it fast: it usually signals a rule or permission before you even parse the full sentence.

When producing your own sentences, ことができます is always a sound choice. Formally correct and well-suited to the JLPT's register — if you're uncertain whether to use it or the potential verb form, ことができます will never be wrong.