Modals of Ability: Can and Could
A complete A2 guide to can and could for present and past ability, including negatives, questions, short answers, and able to.
What Are Modals of Ability?
A modal is a helper verb that comes before a main verb. Modals add meaning such as ability, possibility, permission, or necessity.
For ability, the most important A2 modals are can and could.
| Time | Positive | Negative |
|---|---|---|
| present ability | can | can't / cannot |
| past ability | could | couldn't / could not |
After can and could, always use the base verb.
I can swim.
She could dance when she was five.
They can't ski.
Do not add to, -s, or -ed after a modal.
Can for Present Ability
Use can + base verb to say someone is able to do something now.
I can cook.
My brother can play the guitar.
We can speak English.
Use can't or cannot when someone is not able to do something now.
I can't drive.
She cannot swim.
Cannot is one word. Can't is the short form.
Questions with Can
Use Can + subject + base verb.
| Question | Short Answer |
|---|---|
Can you swim? | Yes, I can. / No, I can't. |
Can he play the piano? | Yes, he can. / No, he can't. |
Can they speak Spanish? | Yes, they can. / No, they can't. |
In short answers, do not repeat the main verb.
Yes, I can.
No, she can't.
Could for Past Ability
Use could + base verb for general ability in the past.
I could ride a bicycle when I was six.
My grandfather could speak three languages.
She could read before she started school.
Use couldn't when someone was not able to do something in the past.
I couldn't swim when I was a child.
They couldn't hear the teacher.
Use a past time marker when needed.
| Time Marker | Example |
|---|---|
| when I was a child | I could climb trees when I was a child. |
| at age five | She could read at age five. |
| last year | He couldn't play guitar last year. |
| 10 years ago | They could ski 10 years ago. |
Could, Was Able To, and Managed To
At A2 level, could is good for general past ability.
I could swim when I was young.
For one successful action in a specific past situation, English often uses was/were able to or managed to.
The fire was dangerous, but everyone was able to escape.
I lost my phone, but I managed to find it.
The negative couldn't works for both general ability and specific situations.
I couldn't swim when I was young.
I looked everywhere, but I couldn't find my phone.
Be Able To
Use be able to when can or could does not fit the grammar.
I want to be able to speak Spanish.
She might be able to come tomorrow.
I haven't been able to sleep well recently.
This lesson focuses on can and could, but be able to is useful when you need another tense or another modal.
Common Mistakes
| Mistake | Better | Why |
|---|---|---|
She can to swim. | She can swim. | Use base verb after can. |
He cans cook. | He can cook. | Can does not add -s. |
I could played the piano. | I could play the piano. | Use base verb after could. |
Can you to help me? | Can you help me? | No to after can. |
I no can drive. | I can't drive. | Use can’t for the negative. |
She could swim now. | She can swim now. | Use can for present ability. |
Practice: Exercises
I ___ speak English.
Summary
Use can + base verb for present ability and can't / cannot + base verb for present inability. Use could + base verb for general past ability and couldn't + base verb for past inability.
After can and could, use the base verb only: no to, no -s, and no -ed. Use be able to when you need another tense or when you talk about one successful action in a specific past situation.