Use :“be” and “can”

Could Mike swim when he was three? No, he couldn’t.

Could Mike swim when he were three? No, he couldn’t.

Could Sarah swim when she was four? Yes, she can.

Could Sarah swim when she was four? Yes, she could

Could Mike read when he was three? Yes, he could.

Could Mike read when he were three? Yes, he could.

Could Sarah read when she were four? No, she couldn’t.

Could Sarah read when she was four? No, she couldn’t.

Could Mike and Sarah ride a bike when they were six? Yes, they could.

Could Mike and Sarah ride a bike when they was six? Yes, they could.