在火上用英语怎么说

"On fire" 是一个英语短语，意思是"着火"。这个短语来源于比喻语。

例句：

The building was on fire. (那幢建筑物着火了)
The chef's food was on fire. (厨师的菜着火了)
He was on fire during the game. (比赛中他表现火爆)