Video lesson · Can / Could / Be Able to
We use could as the past form of can to say that something was possible or allowed, or that somebody had the ability to do something in the past. We use could to talk about skills (learned abilities). Was/were able to is also possible (see the table).
Read the full lesson: Can / Could / Be Able to →
Can / Could
Be Able to
Present and Future Ability
Skills
Unusual Ability
With Verbs of Senses
Theoretical Possibility
Permission / Prohibition
Requests
Offers
Deduction / Negative
Present Use / Summary
Possibility / Ability in the Past
Permission / Prohibition in the Past
With Verbs of Senses / Past
Past Skills
Possibility / Ability in the Past + Fact 
Ability in the FutureGet the app and practice this topic as a game — with XP, streaks and instant feedback.
