“Promettre monts et merveilles” is a fun little French idiom that translates literally to “to promise mountains and marvels”. English meanings include:
- to promise the moon
- to promise the earth
- to promise the sun, moon and stars
A French definition on expressio.fr offers the following meaning: “to promise considerable advantages or benefits, admirable and surprising things.”
Here’s a sample sentence:
- Quand Pierre a eu son nouveau poste il a promis monts et merveilles a son patron mais apres quelques mois il n’avait rien fait. When Pierre got his not job position he promised the moon to his boss. But, after a few months he hadn’t done anything.
synonymous expressions include:
- promettre mers et monde to promise the seas and world (Canadian)
- promettre la lune à quelqu’un to promise the moon to somebody
- éblouir à force de belles promesses to dazzle with beautiful promises
Bonjour! My name is David Issokson. I'm based in Victor, Idaho and have helped hundreds of students to learn French via Skype or Zoom since 2014. 
