Read about using can and could for ability. Then, when you are ready, try these practice exercises with can / could.

General abilities (past and present)

Some abilities are general: you have the skill to do it at any time you like. We use can for present abilities and could for past abilities.

I can play the accordion.

I could play the violin when I was a child.

Specific Abilities in the Past

Not all abilities are general. Some abilities happen only once (or a certain number of times) in a particular situation. In positive sentences, we don't say could, we use was able to.

I was very tired but I could stay awake all night. X

I was very tired but I was able to stay awake all night. ✓

If the sentence is negative, we use could or was able to.

I was very tired, so I couldn't stay awake. ✓

I was very tired, so I wasn't able to to stay awake. ✓

How to make sentences with can and could

Present 

Positive: She can speak 3 languages.

Negative: He can't speak Arabic.

Question: Can you speak any languages?

Past

Positive: They could speak some German when they were 15.

Negative: He couldn't speak any Spanish when he was 15.

Question: Could you speak French when you were 15?

 

Remember: modal verbs don't need an 's' for he/she/it, and always have an infinitive verb (without 'to') after them.

He cans play the piano. X

He can play the piano. ✓

They can to make delicious cakes. X

They can make delicious cakes. ✓

 

Note: if you want to talk about abilities in the future or use other tenses, you need to use be able to in the correct tense.

I will be able to speak perfect French one day. (future)

I have been able to swim since I was five. (present perfect)


Now try these practice exercises with can / could.