back and forth
01
前後に, 行ったり来たり
repeatedly going in one direction and then in the opposite direction
例
The pendulum swung back and forth, marking the passage of time.
振り子は前後に揺れ、時間の経過を示していた。
Back and forth
01
行ったり来たり, 前後
a repetitive movement or action between two points
例
The debate continued in a heated back and forth between the two speakers.
討論は二人のスピーカーの間で熱い行ったり来たりの中で続いた。
