Can vs Could vs Be able to
Master the differences between these three forms of ability
Grammar Explanation
🇬🇧 English
Present ability, permission, possibility
I can swim. / Can you help me?
Past ability, polite requests, possibility
I could swim when I was young. / Could you help me?
Flexible form - all tenses, formal
I will be able to help. / I have been able to work.
🇫🇷 Français
Capacité présente, permission, possibilité
Je sais nager. / Peux-tu m'aider ?
Capacité passée, demande polie, possibilité
Je savais nager quand j'étais jeune. / Pourriez-vous m'aider ?
Forme flexible - tous les temps, formel
Je pourrai aider. / J'ai pu travailler.
Key Rules
✅ Correct Usage
- • I can speak English (present ability)
- • I could run fast when I was young (past ability)
- • Could you pass the salt? (polite request)
- • I will be able to help tomorrow (future)
- • She has been able to work from home (present perfect)
❌ Common Mistakes
- • I
can toswim → I can swim - • He
was cango → He was able to go - • I
will canhelp → I will be able to help - •
Can'tyou help? → Could you help? (more polite)
Common Mistakes to Avoid
I can to swim very well.
❌ Don't use "to" after "can"
I can swim very well.
✅ Correct - no "to" needed
He was can go to the party yesterday.
❌ Can't use "can" with other auxiliary verbs
He was able to go to the party yesterday.
✅ Correct - use "be able to" with other tenses
Practice Exercises
Test your understanding with these exercises