Modal Verbs of Ability: how to talk about your skills in English

Modal verbs are small but incredibly powerful words that help express ability, permission, necessity, or possibility. In this article, we’ll focus on modal verbs of ability — in other words, how to say what you can, could, or will be able to do. Or not do — because, let’s face it, none of us is good at everything. But the good news is — we can always learn!

Contents

1. Modal verbs of ability: how and when to use them
2. Key modal verbs used to express ability: can, could, and be able to
 2.1. Can – present or general ability
 2.2. Could – past ability or polite requests
 2.3. Be able to – a flexible option for any tense
3. How to use modal verbs of ability in different tenses
4. Practice exercises
5. FAQs

Modal verbs of ability: how and when to use them

Modal verbs of ability are modal verbs we use to talk about a person’s skills or capabilities. In other words, they help us express that someone can or cannot do something physically or mentally. For example:

• I can swim.
• She could read when she was four.
• We will be able to travel next year.

Key modal verbs used to express ability: can, could, and be able to

When we talk about someone’s ability to do something — physically, mentally, or depending on the situation — we usually use three main options: can, could, and be able to. But each of them has its own nuances. Let’s break it down!

Can – present or general ability

Can is used when we talk about the ability to do something now or general abilities we have.

• I can speak English.
• She can drive a car.
• Birds can fly.
• I can’t come tomorrow.

Note: We often use can to talk about future ability, but grammatically it only works in the present tense. If you want to talk about ability in the past, use could. For the future, use be able to.

Can is also used to make requests, though it’s less formal than could:

• Can you help me? (neutral, casual)
• Could you help me? (more polite and formal)

Could – past ability or polite requests

Could is typically used to talk about abilities or possibilities someone had in the past. We’ve already mentioned that it’s used for polite requests, but there’s more. Could is also used for hypothetical situations — things that might happen in the present or future.

Let’s look at the examples:

• I could read when I was four.
• She could play the piano very well as a child.
• We could understand him, even though his accent was strong.

Polite requests:

• Could you pass me the salt?
• Could I borrow your phone?

Hypothetical situations:

• We could go to the beach tomorrow, if the weather is nice.
• He could be the one who took the keys.

Exception: If you’re talking about one specific situation in the past where something was successfully done, it’s better to use was/were able to or managed to, rather than could.

✗ I could fix the printer yesterday.
✓ I was able to fix the printer yesterday.

Let’s sum it up in a table:

In the negative form, all three options mean the same thing — the action didn’t happen.

Be able to – a flexible option for any tense

Unlike can and could, which are limited to certain tenses, be able to is a flexible structure that can be used in the present, past, future, and even in complex grammatical forms.

Present tense:

• I am able to understand most of the movie without subtitles.

Past tense:

• She was able to solve the problem quickly.
• They weren’t able to come to the party.

Future tense:

• You will be able to join the class next week.
• I won’t be able to attend the meeting tomorrow.

Other tenses:

• I've never been able to sing in tune.
• By the time you arrive, we will have been able to set everything up.

Good to know: Be able to can sometimes sound more formal than can. It’s also the best option when you need to combine it with other modal verbs (like might, should be able to):

• She might be able to help us later.

We’ll break down how to use be able to in different tenses in the table below.

Here’s a comparative cheat sheet for using modals of ability — can, could, and be able to:

How to use modal verbs of ability in different tenses

Let’s compare how expressing ability changes depending on the tense:

Modal verbs of ability are the key to expressing what you can (or can’t) do. Once you’ve learned can, could and be able to, you’ll be able to talk about your skills in any tense. And with practice — without making mistakes. 

And if you want to learn more about modal verbs in English, we recommend checking out our materials at the following links:

• Modal Verbs of Willingness;
• Modal Verbs of Probability;
• Modal Verbs of Deduction
• Modal Verbs of Necessity
• Modal Verbs of Advice;
• Modal Verbs of Permission.

Practice exercises

Do these simple exercises to remember the rules better.

Task 1. Choose the correct option:

Task 2. Fill in the blanks by choosing the correct modal verb — can, could, or be able to.

FAQs

1. Can we use can in the past?

No, in most cases, the past form is could. However, if you’re talking about a specific situation where something was successfully done, it’s better to use was/were able to. For example:

• I was able to fix the car yesterday. (a successful action in a specific situation)

2. Can we say will can?

No. To express future ability, we use will be able to because can doesn’t have a future form.

3. What’s the difference between could and was able to in the past?

There’s a significant difference:

• Could is used for general abilities in the past.
• Was able to is used for specific situations when something was successfully done.

Examples:

• I could swim when I was a kid.
• I was able to swim across the river yesterday.

However, couldn’t can be used in negative sentences about specific past situations:

• I couldn’t go swimming yesterday.

4. Can I say I couldn’t do it if it’s about a specific situation in the past?

Yes, you can. In negative sentences, couldn’t and wasn’t able to mean the same thing — the action didn’t happen:

• She couldn’t open the door. = She wasn’t able to open the door.