Master both ways to express "can do" in Japanese - ことができる and the potential form られる. Learn when to use each with examples.
•8 min read
Reviewed by GyanMirai Editorial Team•Last reviewed 2025-02-09
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Grammar Comparison JLPT N4 JLPT N4
ことができるvsられる / える
ことができる vs られる: Japanese Potential Forms Complete Guide
Master ことができる and られる potential forms in Japanese. Learn when to use each for expressing ability with clear examples and practice exercises.
Read time: 8 min readSearches: 1,800+ monthlyUpdated: February 17, 2026
Understanding the difference between ことができる (koto ga dekiru) andられる / える (rareru / eru) is one of the most important distinctions in Japanese grammar. This comprehensive guide will help you master when and how to use each one correctly.
Grammar Point A
ことができる (koto ga dekiru)
Can do / Be able to (formal/versatile)
Formal way to express ability. Works with any verb. Often used in written Japanese, formal speech, and when emphasizing the ability itself.
Formation: Verb dictionary form + ことができる
Grammar Point B
られる / える (rareru / eru)
Can do / Be able to (conjugated potential)
Verb conjugation for potential. More common in casual speech. Each verb conjugates differently. Shorter and more natural in conversation.
Formal way to express ability. Works with any verb. Often used in written Japanese, formal speech, and when emphasizing the ability itself.
Verb conjugation for potential. More common in casual speech. Each verb conjugates differently. Shorter and more natural in conversation.
Formation
Verb dictionary form + ことができる
る-verbs: drop る, add られる (食べられる) / う-verbs: う→える (書く→書ける)
JLPT Level
N4
N4
Formality
Formal / Written
Casual / Spoken
Length
Longer
Shorter
Conjugation
No verb change needed
Must conjugate verb
Natural in speech
Less natural
Very natural
Emphasis
On ability as fact
On capability
JLPT Level
N4
N4
Key Differences
1
Formality: ことができる is more formal and written. られる/える is more casual and conversational. Use ことができる in essays, formal announcements, and business writing.
2
Length: ことができる is longer. られる/える is shorter. In casual speech, the shorter potential form is strongly preferred.
3
Versatility: ことができる works with ANY verb without conjugation knowledge. られる/える requires knowing how to conjugate each verb type.
4
Emphasis: ことができる emphasizes the ABILITY or possibility as a fact. られる/える is more about the natural capability in context.
5
Negative Forms: ことができない vs られない/えない. Both work, but ことができない is more formal. 食べられない and 食べることができない mean the same.
When to Use Which?
Follow this decision guide to choose the right grammar point.
Yes
Yes
Use ことができる
No
Use られる / える
No
Yes
Use られる / える
No
Use ことができる
Examples with Explanations
ことができる
日本語を話すことができます。
Nihongo wo hanasu koto ga dekimasu.
I can speak Japanese.
Tip: Formal way to state language ability. Common in resumes, formal introductions.
Context: Job interview or formal self-introduction
られる/える
日本語が話せます。
Nihongo ga hanasemasu.
I can speak Japanese.
Tip: Conversational potential form. Note: を often becomes が with potential.
Context: Casual conversation about abilities
ことができる
この問題を解くことができますか？
Kono mondai wo toku koto ga dekimasu ka?
Can you solve this problem?
Tip: Formal question about ability. Might be used in academic or test settings.
Context: Formal academic context
られる/える
この問題、解ける？
Kono mondai, tokeru?
Can you solve this problem?
Tip: Casual potential question. Much more natural in everyday speech.
Context: Asking a friend casually
ことができる
ここでは泳ぐことができません。
Koko de wa oyogu koto ga dekimasen.
You cannot swim here.
Tip: Formal prohibition/statement of inability. Might be on a sign or in rules.
Context: Official rule or announcement
られる/える
ここでは泳げません。
Koko de wa oyogemasen.
You can't swim here.
Tip: Same meaning but more conversational. Natural in spoken warnings.
Context: Someone telling you verbally
ことができる
生の魚を食べることができますか？
Nama no sakana wo taberu koto ga dekimasu ka?
Can you eat raw fish?
Tip: Polite question about dietary ability/preference.
Context: Formal restaurant or host asking guest
られる/える
刺身、食べられる？
Sashimi, taberareru?
Can you eat sashimi?
Tip: Casual potential. 食べられる is the potential of 食べる.
Context: Friend asking about food preferences
Common Mistakes to Avoid
Mistake #1Using を with potential verbs
Correction: Use が instead of を with potential verbs
Potential verbs often take が instead of を for the object. This is a common pattern.
Wrong: 日本語を話せます。 -- Can speak Japanese (を is less natural)
Correct: 日本語が話せます。 -- Can speak Japanese (が is more natural with potential)
Mistake #2Saying 食べれる instead of 食べられる
Correction: Standard form is 食べられる (ら is kept)
Dropping ら (ら抜き言葉) is common in casual speech but considered incorrect in formal Japanese.
Wrong: 食べれる (casual/non-standard) -- Can eat (ら-dropped, casual)
Correct: 食べられる (standard) -- Can eat (standard potential)
Mistake #3Using ことができる in casual conversation
Correction: Use potential form (られる/える) in casual speech
ことができる sounds stiff in everyday conversation. Use the shorter potential form.
Wrong: 今日、来ることができる？(too formal) -- Can you come today? (overly formal)
Correct: 今日、来られる？/ 今日、来れる？ -- Can you come today? (natural)
Mistake #4Confusing potential with passive (both use られる)
Correction: Context determines meaning
For る-verbs, potential and passive have the same form. Context clarifies: 食べられる = can eat OR is eaten.
Wrong: Always assuming one meaning -- Ignoring context
Correct: りんごが食べられる = (I) can eat the apple / The apple is eaten -- Context determines: ability or passive
Just take the dictionary form and add ことができる. No conjugation needed!
Example: 泳ぐ + ことができる = 泳ぐことができる (can swim)
Tip 3
を → が Shift
When using potential, を often becomes が. Object + が + potential verb.
Example: 漢字を読む → 漢字が読める (can read kanji)
Practice Exercises
Test your understanding with these practice questions. Click on your answer to see if you are correct.
0 / 6 answered
Q1
日本語を読む___。（履歴書で）
I can read Japanese. (on a resume)
Q2
この映画、もう見___？
Were you able to watch this movie already?
Q3
漢字が少し___ようになりました。
I've become able to read kanji a little.
Q4
ここでは写真を撮る___。（看板に）
You cannot take photos here. (on a sign)
Q5
明日、来___？
Can you come tomorrow?
Q6
彼女は3か国語を話す___。
She can speak three languages.
Frequently Asked Questions
In standard/formal Japanese, ら should be kept (食べられる). However, ら抜き言葉 (ら-dropping) is extremely common in casual spoken Japanese, especially among younger speakers. For JLPT, use the standard form. For casual conversation, either is fine.
With potential verbs, the thing you 'can do' often becomes the subject (marked with が) rather than the object (を). 漢字を読む → 漢字が読める. However, を is not grammatically wrong, just less natural. Both 漢字を読める and 漢字が読める are used.
Context! りんごが食べられる: If talking about ability → 'can eat the apple'. If talking about the apple being eaten (by bugs, etc.) → 'the apple is/was eaten'. Passive often has a sufferer/victim nuance or uses に for the agent.
できる is the potential of する. It means 'can do' and is used alone for abilities: 日本語ができる (can do Japanese / know Japanese). It's very common and doesn't need ことができる because it IS the potential form.
Use ことができる: (1) In formal writing (essays, business), (2) When you don't know how to conjugate the verb, (3) When emphasizing the ability/possibility as a notable fact, (4) In official rules or announcements.
Summary
Use ことができる when...
Formal way to express ability. Works with any verb. Often used in written Japanese, formal speech, and when emphasizing the ability itself.
Use られる / える when...
Verb conjugation for potential. More common in casual speech. Each verb conjugates differently. Shorter and more natural in conversation.
Pro Tip: The best way to master the difference is through reading and listening practice. Pay attention to how native speakers use these grammar points in context.
