“could” is a modal verb.

Pronunciation: /kʊd/

In this lesson, you will learn the form of could. You will also learn the many different uses and meanings:

to express possibility
to make a suggestion
to ask for permission
indirect speech (reported speech)
to express ability in the past
to describe sensations in the past
to describe mental processes in the past

Form

Affirmative form

subject  +  “could”  + base form of verb

Negative form

Full form:
subject  +  “could not”  + base form of verb

Contracted form:
subject  +  “couldn’t”  + base form of verb

Question form

“Could” + subject + base form of verb  …. ?

Uses and meaning of “could”

to express possibility

We say “could” to express the idea that something is not certain in the present, future or past:

Possibility in the present or future

We use “could” to express possibility in the present and future.

Example 1:
Jane: What is that over there?
Mark: It’s an aeroplane. (certain in the present)
Mark: It could be an aeroplane. (not certain in the present)

When Mark says “It could be an aeroplane”, it is because he is not sure. Maybe it’s an aeroplane. But it could also be a bird.

Example 2:
Mark: Take an umbrella. It’s going to rain tomorrow. (certain in the future)
Mark: Take an umbrella. It could rain tomorrow. (not certain in the future)

Possibility in the past

We also use could to express possibility in the past.

Form:
could have + past participle

Examples:
Jane: I could have walked to school but I chose to take the bus.

Sarah: I could have bought a new phone but I decided to save my money.

We often use “could have + past participle” in the following situations:

to express regret

If we are reflecting on the past and thinking about something that was possible but didn’t happen, we are often feeling regret in the present.

Examples:
I could have been a doctor.
I could have been rich.

to criticise

If someone had the opportunity to do something in the past, but didn’t do it, we use “could have + past participle” to criticise them.

Examples:
You could have cleaned the bathroom!

Why did you take my phone? You could have asked me!

to make a suggestion

We use “could” to make a suggestion or proposal.

Examples:
Jane: I’m really tired.
Mark: I could cook dinner.

David: I don’t understand these reports.
Sarah: I could explain them if you want.

to ask for permission

We use “could” to ask for permission or to request something. This is usually in the question form. Don’t forget the question mark (“?”) at the end of the sentence.

Examples:
Could I borrow your phone?
Could you carry my bag please?

Indirect speech (reported speech)

When we use indirect speech, we use “could” after past reporting verbs where “can” was used in direct speech. “could” is therefore being used as a past form of “can“.

Examples:

Direct speech:
Andrew said, “You can visit my website.”
Indirect speech:
Andrew said that we could visit his website.

Direct speech:
Jane said, “I can carry the bag.”
Indirect speech:
Jane said that she could carry the bag.

to express ability in the past

We use the modal verb “could” to express ability in the past.

Examples:

When Jane was a student, she could study for 10 hours a day.

When Mark was young, he could play the guitar.

to describe sensations in the past

We use “could” with verbs of the senses to describe sensations in the past.

Example:

Someone was smoking a cigar. I could smell it.

to describe mental processes in the past

We use “could” with verbs of mental processes to describe mental processes in the past.

Examples:

She talked slowly. I could understand her.
I wanted to call her but I couldn’t remember her number.

Other lessons

Modal verb WOULD
Irregular verbs in English
Conditionals in English
IELTS online course and writing corrections
All lessons

Video lesson