Johnny said to his mother, “I don’t know how to do this exercise.” → Johnny said to his mother .

↳ Johnny said to his mother he didn’t know how to do that exercise.
Giải thích: câu tường thuật, lùi thì động từ, this => that.
Dịch: Johnny nói với mẹ anh ấy anh ấy không biết làm bài tập đó như thế nào.

Johnny said to his mother: “I don’t know how to do this exercise.” → Johnny said to his mother ______________________________________.

Johnny said to his mother: “I don’t know how to do this exercise.”

→ Johnny said to his mother ______________________________________.