B1Modals and verb patterns

Can, could and be able to

Use can/could for general ability and be able to when tense or a specific successful achievement requires a fuller form.

Overview

What this grammar does

Use can/could for general ability and be able to when tense or a specific successful achievement requires a fuller form.

Form and rules

How it works

Use can for present general ability and could for general past ability.

Use be able to when English needs an infinitive, perfect or future form: to be able to, have been able to, will be able to.

For one successful action in a particular past situation, was/were able to or managed to is often clearer than could.

Could is natural for general skills in the past: I could swim when I was five.

Couldn't can describe both general past inability and failure in a specific situation.

A closer look

Meaning and use

Could is natural for general skills in the past: I could swim when I was five.

Couldn't can describe both general past inability and failure in a specific situation.

Examples

See the pattern in complete sentences

I can speak two languages.

She could read before she started school.

We were able to solve the problem in the end.

I'll be able to help tomorrow.

He hasn't been able to sleep well lately.

Common mistakes

What to avoid

When I was ten, I was able to swim very well.

When I was ten, I could swim very well.

This describes general ability over a period in the past, so could is the most natural choice.

After several attempts, we finally could open the door.

After several attempts, we finally were able to open the door.

A specific successful achievement in the past is naturally expressed with were able to.

Ready to practise?

The test combines multiple choice, gap completion, error correction, and sentence building so students have to recognise and produce the grammar, not simply reread the rule.

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