突然掉头用英语怎么说

"suddenly turn around" 可以用 "make a sudden U-turn" 或 "do a sudden about-face" 来表示。

"U-turn" 是源自于驾驶中的“U”型转弯，而 "about-face" 则来自军事术语，意思是“180 度转身”。

例句：

He made a sudden U-turn on the highway and caused a car accident.
他突然在高速公路上掉头，导致了一场车祸。

The soldier did a sudden about-face and marched back to the barracks.
士兵突然转身，向兵营行进。