Intermediate 📐 Grammar · #273 of 305

Ability in the Past: Could vs Was Able To

could = general ability; was able to = one occasion.

Examples

  • I could swim at five.
  • I was able to escape.

Key rules

  • Could = general ability in the past (I could swim at five)
  • Was or were able to = one specific success (I was able to escape)
  • In negatives both can be used (I couldn't escape)
  • Could is not used for one particular achievement in affirmative sentences

Common mistakes

  • I could escape from the fire last night → I was able to escape from the fire last night
  • He can swim when he was young → He could swim when he was young
💡 Tip: One event means was able to.
Practise this topic in the appPractise Intermediate quiz
← Obligation in the Past: Had To, Was Allowed ToModals of Possibility: Could, May, Might, Can't →

Related Intermediate topics

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Present Perfect Continuous

have been + -ing stresses duration up to now.

Past Perfect

had + past participle for an earlier past action.

Past Perfect Continuous

had been + -ing for duration before a past moment.

Future Continuous

will be + -ing for actions in progress at a future time.

Future Perfect

will have + past participle for completion before a future time.

Future Perfect Continuous

will have been + -ing for duration up to a future point.