Can, could, be able to: Ability and possibility

You can practice with B1 exercises, and you can do them. Use clear explanations and interactive English tests to improve your grammar of ability and possibility.

Can, Could, Be Able To: Ability and Possibility Exercises

It’s important to know how to use can, could, and be able to if you’re learning English at the B1 level. These forms help you talk about what you can do and what might happen in the past, present, and future.

With examples and tips, this guide makes the differences clear.

Using CAN for Present Ability

We use “can” to talk about what we can do right now.

Structure:

Subject + can + base verb

Examples:

• I can swim very well.
• She can speak two languages.
• They can solve difficult problems.

Negative form:

• I cannot (can’t) drive.
• He can’t understand the question.

Question form:

• Can you play the piano?
• Can she help us?

We say “can” when someone can do something right now.

Using COULD for Past Ability

We use could to talk about what we could do in the past.

Structure:

Subject + could + base verb

Examples:

• I could read when I was five.
• She could run very fast when she was younger.
• They could see the mountains from their house.

Negative form:

• I could not (couldn’t) hear you.
• He couldn’t finish the task.

Question form:

• Could you swim when you were a child?

Important note:
Could refers to general past ability, not specific success.

Correct:

• I could swim when I was young.

We often use was able to for certain situations.

Correct:

• I was able to finish the report yesterday.

Using BE ABLE TO for Ability in Different Tenses

We use “be able to” when we need to talk about ability in different tenses, like the future or perfect tenses.

Structure:

Subject + be (am/is/are/was/were/will be) + able to + base verb

Present:

• I am able to help you.
• She is able to solve the problem.

Past:

• He was able to find his keys.
• They were able to complete the project.

Future:

• I will be able to drive next year.
• She will be able to join the meeting tomorrow.

We say “be able to” because “can” doesn’t have a future form.

Incorrect:

• I will can drive.

Correct:

• I will be able to drive.

Can and Could for Possible

We can also use can and could to talk about what might happen.

CAN for general possibility

• It can be very cold in winter.
• This road can be dangerous.

COULD for possible situations (less certain)

• It could rain later.
• She could be at home now.

Could often shows less confidence than can.

What is the difference between CAN and BE ABLE TO?

Can and be able to often mean the same thing now.

• I can help you.
• I am able to help you.

But “can” is more common in everyday English.

We normally say “be able to” when:

• Talking about future ability
• Using perfect tenses
• Describing specific past achievements

Example:

• She was able to fix the computer yesterday. (specific success)

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