10 sentences of could

When actual past achievements are mentioned, we usually use was/were able to or managed to but not could in affirmative clauses.

This is because they are facts, rather than possibilities:

I was able to/managed to buy a wonderful bag to match my shoes.

Not: I could buy a wonderful bag to match my shoes.

We hired a car and we were able to/managed to drive 1,000 miles in one week.

Not: We hired a car and we could drive 1,000 miles in one week.

We use could to talk about past ability:

When I was young, I could easily touch my toes.

We use could have + -ed form to talk about possibility in the past:

I could have been a lawyer.

They could have taken a taxi home instead of walking and getting wet.

Janette couldn’t have done any better.

When we want to guess or predict something, we use couldn’t as the negative form of must.

We use couldn’t have + -ed form as the negative form of must have + -ed. Couldn’t and couldn’t have + -