A: Could you swim at the age of six?
B: Yes, I could./No, I couldn't.
A: Could you read at the age of five?
B: Yes, I could./No, I couldn't.
A: Could you write at the age of seven?
B: Yes, I could./No, I couldn't.
A: Could you play the piano at the age of eight?
B: Yes, I could./No, I couldn't.
A: Could you ride bikes at the age of nine?
B: Yes, I could./No, I couldn't.