mr

In a sentence

• Bonjour, Monsieur Dupont, comment allez-vous?

  Good morning, Mr. Dupont, how are you?

  Here, 'Mr.' or 'Monsieur' serves as a respectful title used before a man's last name to address him formally.

• Le monsieur au chapeau noir est mon professeur.

  The gentleman with the black hat is my teacher.

  In this case, 'Monsieur,' translated as 'gentleman,' is used to refer to an adult man.

• Excusez-moi, monsieur, pourriez-vous m'aider?

  Excuse me, sir, could you help me?

  Here, 'monsieur' is used in polite address to an unknown man.