could

できる

過去に何かをする能力があったことを表す。

やさしい英語で： Was or were able to do something in the past.

• I could swim at six.
• She could speak French as a child.
• Could you ride a bike when you were five?

使い方： could + base verb (He could run very fast when he was young.)

類義語： was able to, were able to

よく使う表現： could swim, could read, could speak

できる

何かをすることが、選べる方法の一つだと表す。

やさしい英語で： Used to say that an action is available as a choice.

• We could walk home.
• You could ask your teacher instead.
• She could take the bus or ride her bike.

使い方： could + base verb (You could use my phone.)

よく使う表現： could go, could try, could stay

してもいい

何かをしてもよいか、丁寧に尋ねるときに使う。

やさしい英語で： Used to ask politely whether you are allowed to do something.

• Could I sit here?
• Could we leave a little early?
• Could I borrow your pen, please?

使い方： Could I/we + base verb? (Could I open the window?)

よく使う表現： could I borrow, could we use, could I leave

できる

状況が違えば、何かができるだろうということを表す。

やさしい英語で： Would be able to do something if a situation were different.

• I could help if I had time.
• If she were taller, she could reach the shelf.
• We could travel more if tickets were cheaper.

使い方： could + base verb + if… (I could buy it if I saved enough money.); wish + subject + could + base verb (I wish I could visit you.)

類義語： would be able to

よく使う表現： could do something, could afford something, could be