What does each sentence express?
- He can speak five languages.
Ability in the present
- I could lift heavy weights when I was twenty, but now I can’t.
Past ability/inability in the present.
- The match wasn’t easy, but they were able to win.
Past ability
- I wasn’t able to get tickets to the show.
Inability in the past.
- We will be able to join you in two hours.
Ability in the future.