$\text{@su}$

`1`, I could play chess when I was six

`2`, We couldn't play football because it was raining

`3`, I said she cold not understand anything.

`4`, When you were five, could you speak English?

`5`, When my brother was two he could draw pictures

hoặc My brother could draw pictures when he was two.

`6`, Could the robots clean the house ten years ago?

`7`, This suitcase was very heavy so I couldn't lift it.

`8`, Dave could play tennis well when he was young.

hoặc When Dave was young he could play tennis

Bonus: S + could + (not) + Vbare + when + S + was/were + ...

$\text{#BTS}$