Languages › French Fais Gaffe: French Phrase Explained Share Flipboard Email Print Keren Su / Getty Images French Vocabulary Pronunciation & Conversation Grammar Resources For Teachers By ThoughtCo Updated February 17, 2019 Expression: Fais gaffe !Pronunciation: FAY GAFFMeaning: Be careful! Watch out!Literal translation: Make mistake!Register: informalNotes: The French expression fais gaffe is interesting because it means just the opposite of its literal translation. Faire une gaffe means "to make a mistake, to blunder," so you would think that "be careful!" would be something more like ne fais pas de gaffe! Apparently leaving out une is enough to turn the meaning around. You can also say Fais gaffe à toi to mean "Watch yourself."ExampleÇa peut être dangereux: Fais gaffe!That can be dangerous: Be careful!