片語
相似詞 slim chance / improbable
搭配詞 emergency / natural disaster
【單詞解析】
電影院裡面經常見到的標示 「In the unlikely event of a fire, please use the emergency exit closest to you.（萬一有火災，請就最近的出口離開。）」如果你寫成「If / In case there is a fire…」也可以，可是「In the unlikely event」更強調「萬一」之不可能性，言下之意，本戲院安全措施完善，著火機會極小，「萬一」有火災。這麼一解釋，大家就了解in the unlikely event這句片語的好用之處，既提醒火災時如何逃生，也暗示本戲院是很安全的。同理，如果你想說我老公老實可靠，怎會有外遇，就可以說「In the unlikely event that my husband has an affair…」這比「If my husband has an affair…」更具人妻的尊嚴。
此片語如果後面跟著名詞，就用of，如接子句，就用that，這是很基本的文法規則。另外以文意來說，此片語不能單獨存在，一定要加上將採行的動作，如 In the unlikely event that he doesn’t show up, can you perform instead?（萬一他沒來，你可以代演嗎？）」這樣才算把話說完。
與此片語意思相似，而且可以拼在一起用的是slim chance（機會渺茫），「There is only a slim chance that I’ll ever meet Michael Jordan. But in the unlikely event that I actually come across him, I will ask him to autograph my basketball.（我不太可能遇見 Michael Jordan. 但是萬一哪天真的碰上了，我要請他在我的籃球上簽名。）」
【例句】
萬一停電，請走樓梯而不要用電梯。
In the unlikely event of a power outage, use the stairs instead of the elevator.
萬一四點的時候他們一個人都沒到，我們就得取消此會議。
In the unlikely event that none of them can make it here by 4 p.m., we will have to cancel the meeting.
萬一迫降在水面上，椅子下可找到救生衣。
In the unlikely event of an emergency water landing, you may find a flotation device beneath your seat.