Usage of the French Expression Tout à Coup

The French expression tout à coup (pronounced too ta koo) means "all of a sudden." It literally translates to "all at (a) blow." Its register is normal. ​​Tout à coup is a very common French expression which indicates that something happened abruptly and unexpectedly.

• Sans dire un mot, elle a tout à coup pris son sac et est partie.
• Without a word, she suddenly picked up her bag and left.
• Tout à coup, j'ai perdu l'appétit.
• All of a sudden, I lost my appetite.

Tout à coup is often used interchangeably—though technically incorrectly—with the French expression tout d'un coup.