2.
1. couldn't.
2. could.
3. couldn't
4. could.
5. couldn't
6. could.
3.
1. Could you play chess when you were ten years old?
2. Could you ride a bike when you were six years old?
3. Could you send a text message when you were two years old?
4. Could you swim when you were eight years old?
5. Could you speak English when you left primary school?