The English phrase 'good night, sweet dreams,' translates into French as 'bonne nuit, doux reves.'
'Good' in French is 'bon', while 'night' is 'nuit'. Due to the way certain adjectives work with nouns in French, the two words together become 'bonne nuit.'
'Sweet' in French becomes 'doux', and the French for dreams is 'reves', which is where we get the English word 'reverie'.
The French phrase 'fais de beaux rêves' means 'make beautiful dreams' and is a more popular phrase than 'bonne nuit, doux reves' so perhaps use this instead when saying goodnight!
Other French Farewells
Goodbye - Au revoir
'bye - salut
See you in a moment - A tout de suite
See you soon - A bientot
See you tomorrow - A demain
Have a nice evening - bonne soiree
Learn more French ways to say goodbye with this film: