
How Can Writing Formal Letters Improve Your French? The complexity and artistry that go into formal letter writing will teach you the ins and outs of advanced. When writing formal letters, always use “vous” and never “tu”. When using you in the singular form, tu implies intimacy and informality. Salutations (Les saluts) ; Messieurs, Dear Sirs ; Monsieur, Dear Sir ; Madame, Dear Madam ; Mademoiselle, Dear Miss ; Monsieur le Directeur, Dear.