Translation guide
The English word 'able' is most commonly expressed in Japanese through potential verb forms, the phrase ことができる, or adjectives like 可能な. The best choice depends on whether you're talking about ability, possibility, or a state of being capable.
私は日本語が話せます。
I am able to speak Japanese.
彼は有能な学生です。
He is an able student.
Expressing that someone has the skill, capacity, or opportunity to perform an action.
Japanese verbs have a special potential form that directly means 'can do' or 'is able to do'. This is the most natural and common way to express ability. For ru-verbs, replace る with られる; for u-verbs, change the final vowel to its え-row equivalent and add る. Irregular verbs: する → できる, 来る → 来られる.
私は日本語が話せます。
I am able to speak Japanese.
彼は泳げる。
He can swim.
A more formal or written way to express ability. It literally means 'the thing of doing V is possible'. It can be used with any verb, but in casual speech the potential form is preferred.
彼は英語を話すことができます。
He is able to speak English.
A noun or na-adjective meaning 'possible' or 'feasible'. Often used in compounds or formal contexts. Not used alone to say 'I am able to...'.
実現可能な計画
a feasible plan
Expressing that a situation allows an action, or permission is granted.
The potential form also covers circumstantial ability and sometimes permission. Context makes it clear.
明日は早く来られますか？
Will you be able to come early tomorrow?
Used specifically for permission: 'it's okay to do'. Not for ability.
ここで写真を撮ってもいいですか？
Am I able to take photos here? (Is it allowed?)
Describing someone as competent, skilled, or talented.
A na-adjective meaning 'able', 'capable', 'competent'. Used for people.
彼は有能な弁護士だ。
He is an able lawyer.
The potential form of する, often used as an adjective meaning 'competent' or 'good at one's job'.
できる社員
an able employee
Expressing ability to see, hear, etc.
The potential form is shorter and more conversational. ことができる is slightly more formal and often used in writing or polite speech. Both are correct, but the potential form is more common in daily life.
日本語が話せる。
I can speak Japanese. (casual)
日本語を話すことができる。
I am able to speak Japanese. (more formal)
While 可能 means 'possible', it is not used to say 'I am able to do something' in the same way as the potential form. Saying 私は日本語が可能です is unnatural. Use the potential form or ことができる instead.