Translation guide
Expresses ability or possibility. In Japanese, this is most commonly conveyed through the potential form of verbs, or using constructions like ことができる. The choice depends on formality, transitivity, and the type of ability.
To say that someone can do something, or that something is possible.
The most natural and common way to express ability. Formed by changing the verb ending: for ru-verbs, replace る with られる; for u-verbs, change the final -u to -eru. Note that られる is often shortened to れる in casual speech (ら抜き言葉).
I can speak Japanese.
Can you come tomorrow?
A more formal or written way to express ability. Often used when the potential form might be ambiguous or when emphasizing the ability itself. Can be used with any verb.
He can play the piano.
A noun meaning 'possible' or 'feasible'. Used in formal or technical contexts, often in compounds like 可能だ (is possible) or 可能にする (make possible).
To express that someone has acquired a skill through effort.
Indicates a change in state: becoming able to do something. Often used when talking about learning a new skill.
To say that something is possible due to circumstances, not necessarily skill.
The potential form also covers situational possibility. Context makes it clear.
Can I smoke in this room?
To ask for or grant permission.
The standard way to ask for permission. Literally 'is it okay if I...?'
May I open the window?
To say that someone cannot do something, or something is impossible.
The negative of the potential form. For ru-verbs: られない; for u-verbs: -enai (e.g., 話せない).
I can't read kanji.
While both express ability, the potential form is more conversational and natural in daily speech. ことができる is slightly more formal and common in writing. For some verbs, the potential form can be ambiguous (e.g., 食べられる could be potential or passive), so ことができる clarifies ability.
can eat vs is eaten
I can't eat natto.
a feasible plan
I became able to speak Japanese.
A slightly more casual version of the above, using the potential form directly.
I became able to swim.
Also used for circumstantial possibility, often in more formal settings.
You can take photos here.
A more formal way to ask for permission, meaning 'do you mind if I...?'
Do you mind if I sit here?
Formal/written negative ability.
He cannot come.
In casual speech, the ら in the potential form of ru-verbs is often dropped. For example, 食べられる becomes 食べれる. This is considered incorrect in formal writing but is extremely common in spoken Japanese.
When using the potential form, the object particle を often changes to が. For example, 日本語を話す → 日本語が話せる. This emphasizes the object as the thing that is 'able to be done'. However, を is also acceptable in many cases, especially with ことができる.
She can play the violin.