Potential vs Ability

Understanding the Difference

Japanese has multiple ways to express "can," each with subtle differences in meaning and usage:

Expression	Focus	Usage
Potential form	Natural ability/skill	Most common
ことができる	Formal ability	Written/formal
できる	General capability	する verbs
〜得る (うる/える)	Theoretical possibility	Formal/written

Potential Form: Natural Ability

Focus: Learned skills and capabilities

日本語が話せます
"I can speak Japanese"
(I have the skill)

泳げる
"I can swim"
(I have the ability)

ピアノが弾ける
"I can play piano"
(I learned how)

Best for:

• Acquired skills
• Physical abilities
• Habitual capabilities
• Natural conversation

ことができる: Formal Ability

Focus: Accomplishment or possibility

日本語を話すことができます
"I am able to speak Japanese"
(More formal statement)

ついに完成させることができた
"I was finally able to complete it"
(Emphasizes achievement)

Best for:

• Formal situations
• Written Japanese
• Emphasizing achievement
• Polite expressions

できる: General Capability

Focus: General skill or possibility

料理ができます
"I can cook"
(General ability)

今日はできません
"I can't today"
(Not possible today)

彼はなんでもできる
"He can do anything"
(General capability)

Best for:

• する verbs (料理する → 料理ができる)
• General statements
• Possibility (not specific skills)

Situational Ability vs Inherent Ability

Situational (right now, today)

Often uses potential form or できる:

今日は早く帰れます
"I can go home early today"
(Circumstance allows it)

明日は会えません
"I can't meet tomorrow"
(Schedule doesn't permit)

今ならできる
"I can do it now"
(Current situation allows)

Inherent (permanent skill)

Can use any form, but potential is most natural:

日本語が話せます
"I can speak Japanese"
(I have the skill)

泳げる
"I can swim"
(I know how)

Permission vs Ability

Pure ability: Use potential form

漢字が読める
"I can read kanji"
(I have the skill)

Permission: Use てもいい

ここで写真を撮ってもいいですか？
"May I take photos here?"
(Asking permission)

Not: ここで写真が撮れますか？ ⚠️
(This asks about physical possibility, not permission)

Both ability AND permission:

Sometimes potential form can imply both:

ここで泳げますか？
"Can you swim here?"
Could mean: Is swimming possible/allowed here?

Physical vs Learned Ability

Physical capability

重い物が持てる
"I can lift heavy things"
(Physical strength)

100メートル走れる
"I can run 100 meters"
(Physical stamina)

暗い所でも見える
"I can see even in dark places"
(Natural ability)

Learned skill

ピアノが弾ける
"I can play piano"
(Learned skill)

プログラミングができる
"I can program"
(Learned skill)

車が運転できる
"I can drive"
(Learned skill)

Comparing Common Patterns

"Can speak Japanese"

Most natural (conversation):

日本語が話せます
Potential form - casual, natural

Formal (business/writing):

日本語を話すことができます
ことができる - polite, formal

General (skill mention):

日本語ができます
できる - general ability

"Can swim"

Skill you have:

泳げます
Potential form

Right now possibility:

今日は泳げます
"I can swim today"
Potential form (circumstance)

Achievement:

ついに25メートル泳ぐことができた
"I was finally able to swim 25 meters"
ことができる (emphasis on achievement)

Natural Visibility/Audibility

見える (mieru) - Can see/is visible

Natural visibility:

窓から海が見える
"The ocean is visible from the window"
(It's naturally there to see)

Not the potential form of 見る!

見られる (mirareru) - Can watch/see

Ability to see/watch:

この映画が見られますか？
"Can you watch this movie?"
(Do you have ability/permission?)

This IS the potential form of 見る.

聞こえる (kikoeru) - Can hear/is audible

Natural audibility:

音楽が聞こえる
"I can hear music"
(Sound reaches my ears naturally)

聞ける (kikeru) - Can listen/ask

Ability to listen:

このラジオが聞けますか？
"Can you listen to this radio?"
(Ability/possibility to listen)

Theoretical vs Actual Possibility

〜得る (うる/える) - Theoretical possibility

Formal, written:

そのようなことはあり得る
"Such a thing is possible"
(Theoretically possible)

考え得る全ての方法
"All conceivable methods"
(All methods one could think of)

Not common in speech!

Potential form - Actual possibility

明日は行けます
"I can go tomorrow"
(Actually possible for me)

それはできる
"That can be done"
(Practically possible)

Expressing Difficulty

できる with modifiers

なかなかできない
"It's difficult / I can't quite do it"

簡単にできる
"I can do it easily"

すぐにできる
"I can do it right away"

Potential with effort phrases

頑張れば話せるようになる
"If you try hard, you'll be able to speak"

練習すれば弾けるようになる
"With practice, you'll be able to play"

Common Mistakes

Mistake 1: Using potential for permission

Wrong context: ここで食べられますか？ ⚠️
For permission: ここで食べてもいいですか？ ✓
"May I eat here?"

Potential is OK if asking about rules:
ここで食べられますか？ ✓
"Is eating allowed here?" / "Can one eat here?"

Mistake 2: Overusing ことができる in casual speech

Unnatural: 泳ぐことができる？ ⚠️
Natural: 泳げる？ ✓
"Can you swim?"

Mistake 3: Confusing 見える with 見られる

見える = visible (no volition)
窓から海が見える ✓
"The ocean is visible from the window"

見られる = can watch (with volition)
映画が見られる ✓
"Can watch a movie"

Mistake 4: Wrong particle

Wrong: 日本語を話せます ❌
Right: 日本語が話せます ✓
"I can speak Japanese"

But OK: 日本語を話すことができます ✓

Nuance Comparison Chart

Situation	Best Choice	Example
Casual skill	Potential	泳げる
Formal statement	ことができる	泳ぐことができます
Achievement	ことができる	ついに泳ぐことができた
する verbs	できる	料理ができる
Natural visibility	見える	海が見える
Permission	てもいい	泳いでもいい
Theoretical	〜得る	あり得る

Practice Choosing the Right Form

Scenario 1: Job Interview

Less natural: 日本語が話せます ⚠️
Better: 日本語を話すことができます ✓
"I can speak Japanese"
(Formal situation → use ことができる)

Scenario 2: Chatting with Friends

Unnatural: 泳ぐことができる？ ⚠️
Natural: 泳げる？ ✓
"Can you swim?"
(Casual → use potential form)

Scenario 3: Achievement

Good: ついに合格できた ✓
Better: ついに合格することができた ✓
"I was finally able to pass"
(Achievement → ことができる emphasizes it)

Scenario 4: Restaurant

For permission: ここで食べてもいいですか？ ✓
"May I eat here?"

For possibility: ここで食べられますか？ ✓
"Is eating possible here?"

Different meanings!

Ability Development Over Time

Learning progression

今は話せません
"I can't speak now"

少し話せるようになりました
"I've become able to speak a little"

今は話せます
"I can speak now"

Using なる (become)

話せるようになる
"Become able to speak"

できるようになる
"Become able to do"

見えるようになる
"Become able to see"

Context-Dependent Meanings

見られる can mean three things:

1. Potential (can see/watch):

この映画は見られますか？
"Can you watch this movie?"

2. Passive (is seen):

人に見られた
"I was seen by someone"

3. Respect (honorific watch):

先生がテレビを見られる
"The teacher watches TV"

Context makes it clear!

Summary Table

Expression	Formality	Usage	Example
話せる	Casual-Polite	Natural speech	日本語が話せる
話すことができる	Formal	Written/formal	日本語を話すことができる
日本語ができる	Neutral	General ability	日本語ができる
見える	Neutral	Natural visibility	海が見える
聞こえる	Neutral	Natural audibility	音楽が聞こえる
〜得る	Very formal	Theoretical	あり得る

Quick Decision Guide

Ask yourself:

1. How formal is the situation?

• Very formal → ことができる
• Normal/casual → potential form

2. What are you expressing?

• Skill/ability → potential form or ことができる
• Permission → てもいい
• Natural sense → 見える/聞こえる
• General capability → できる

3. Is it a する verb?

• Yes → できる (料理ができる)
• No → potential form (泳げる)

4. Are you emphasizing achievement?

• Yes → ことができる
• No → potential form

Practice Sentences

Basic Choice

Casual: 日本語が話せる
Formal: 日本語を話すことができます
General: 日本語ができる
All mean: "I can speak Japanese"

Natural Senses

海が見える (not 見られる for visibility)
"The ocean is visible"

音が聞こえる (not 聞ける for natural hearing)
"I can hear a sound"

Achievement

ついに完成させることができました
"I was finally able to complete it"
(Emphasizes the achievement)

Permission

写真を撮ってもいいですか？
"May I take photos?"
(Asking permission, not ability)

Advanced: Subtle Nuances

Potential form: More direct

明日行ける
"I can go tomorrow"
(Direct statement of ability)

ことができる: More tentative/polite

明日行くことができます
"I am able to go tomorrow"
(More formal, polite statement)

できる: Most general

明日ならできる
"If it's tomorrow, I can (do it)"
(General possibility)

Related Grammar Points

• Potential Form - Conjugation and basic usage
• ことができる - Formal ability expression
• 〜やすい/〜にくい - Easy/hard to do
• 〜得る (うる/える) - Theoretical possibility
• 〜ようになる - Come to be able to
• Permission (てもいい) - May/can (permission)
• 見える/聞こえる - Natural visibility/audibility