B1-ABILITY AND POSSIBILITY; CAN, COULD AND BE ABLE TO
Explicación
Tower Languages
Online Learning is Today
Created by Julio Ángel R. — Bilingual Educator
Ability and Possibility — Can, Could & Be Able To
Grammar Guide
📌 Three ways to express ability and possibility
🔷 1. CAN
CAN
COULD
BE ABLE TO
Each form is used in specific tenses and contexts. Knowing when to use each one is key to speaking naturally.
🔹 CAN — Present Ability & Possibility
⚙️ Structure
Subject + can + base verb
✅ Ability (Present)
I can swim.
She can speak English.
They can play the guitar.
✅ Possibility
It can rain today.
This road can be dangerous.
Anyone can make mistakes.
❌ Negative
I can't drive.
He can't cook.
❓ Questions
Can you dance?
Can she run fast?
🔹 COULD — Past Ability & Possibility
✅ Past Ability (General)
I could read at age 5.
She could swim as a child.
They could run very fast.
✅ Possibility (Less Certain)
It could rain later.
She could be at home.
We could win the game.
❌ Negative
I couldn't understand the lesson.
He couldn't ride a bike.
❓ Questions
Could you play piano when you were young?
💡 Remember
could = maybe — expresses uncertainty about possibility
🔹 BE ABLE TO — All Tenses
We use be able to when we need ability in a tense where can cannot be used.
📅 Present — same meaning as CAN (less common)
I am able to help you.
She is able to solve the problem.
💡 Tip
In the present, can sounds more natural: "I can help you."
🏆 Past — Specific Success (use instead of COULD)
The door was locked, but I was able to open it.
She was able to finish the race.
❌ Incorrect
I could open the door. (specific moment)
✅ Correct
I was able to open the door.
🔮 Future — CAN has no future form
I will be able to drive next year.
She will be able to travel soon.
🔗 After "to" — use BE ABLE TO, not CAN
I want to be able to speak English.
She needs to be able to use a computer.
They hope to be able to travel.
| Use | Present | Past | Future |
|---|---|---|---|
| General Ability | can | could | will be able to |
| Specific Past Success | — | was / were able to | — |
| Possibility | can | could | could |
| After "to" | be able to (all tenses) | ||
CAN
Present ability
General possibility
Most natural in present
General possibility
Most natural in present
COULD
General past ability
Less certain possibility
= "maybe"
Less certain possibility
= "maybe"
BE ABLE TO
Specific past success
Future ability
After other verbs (want, need…)
Future ability
After other verbs (want, need…)
🧠 Quick Contrast — All in One
I can swim. → general ability now
I could swim when I was 5. → past ability
I was able to swim across the river yesterday. → specific success
I will be able to swim after training. → future ability
It can rain. → it's possible
It could rain. → maybe (less certain)
Ejercicio 1
Tower Languages
Online Learning is Today
Created by Julio Ángel R. — Bilingual Educator
Can, Could & Be Able To — Quiz
— / 12
Instrucción: Select the correct modal verb to complete each sentence. Choose from the dropdown inside each question.
CAN — Present ability
COULD — Past ability / possibility
BE ABLE TO — Future / after verbs / specific success
1
I
swim when I was five.
2
She
speak three languages now.
3
They will
travel next year.
4
I
open the door yesterday.
5
He
run very fast when he was younger.
6
We want to
understand English.
7
I
help you now.
8
She
finish the race yesterday.
9
They
play chess when they were children.
10
I hope to
drive soon.
11
It
rain later.
12
She
solve the problem now.
Check Answers ✓
Ejercicio 2
Tower Languages
Online Learning is Today
Created by Julio Ángel R. — Bilingual Educator
Can, Could & Be Able To — Practice
— / 12
Instrucción: Select the correct option from the dropdown inside each sentence to complete the gap correctly.
CAN — Present ability
COULD — Past ability / possibility
BE ABLE TO — Future / after verbs / specific success
1
She
finish the project before the deadline.
2
When I was younger, I
run very fast.
3
We hope to
solve the problem soon.
4
He
speak French when he lived in Paris.
5
You
join us later if you want.
6
work late is sometimes necessary in this job.
7
They
attend the meeting yesterday.
8
If you practice more, you will
play better.
9
I
open the window because it was stuck.
10
She
help you now.
11
travel is one of his biggest dreams.
12
Last night, we
see the stars clearly.
Check Answers ✓