In French, when an adjective is followed by an infinitive verb, the preposition de is frequently placed between them. This structure creates a direct relationship between the quality expressed by the adjective and the action denoted by the verb. Unlike the noun + de + infinitive construction, this pattern specifically links descriptive qualities to actions.

Structure and Usage

The basic formula is:
Adjective + de + Infinitive

This construction appears in various contexts to express:

• Emotional reactions to actions
• Evaluations of actions
• Personal characteristics in relation to actions
• Necessity or importance of actions

Complete Sentence Examples

1. Je suis heureux de te revoir. (I’m happy to see you again.)
2. Elle était surprise d’apprendre la vérité. (She was surprised to learn the truth.)
3. Nous sommes prêts de commencer le projet. (We’re ready to start the project.)
4. Il est important de bien préparer l’examen. (It’s important to prepare well for the exam.)
5. Tu es courageux de dire la vérité. (You’re brave to tell the truth.)
6. C’est difficile de comprendre cette théorie. (It’s hard to understand this theory.)
7. Elle semble contente de participer. (She seems happy to participate.)
8. Ils sont fiers d’avoir gagné. (They’re proud to have won.)
9. Je suis désolé de t’avoir fait attendre. (I’m sorry to have made you wait.)
10. Il est impossible de prévoir l’avenir. (It’s impossible to predict the future.)

Important Notes on Usage

1. Preposition Variation: While de is common, some adjectives require à:

• Ce problème est facile à résoudre (This problem is easy to solve)
• Elle est lente à comprendre (She’s slow to understand)

2. Formal vs. Informal: In spoken French, de is sometimes omitted in rapid speech:

• Je suis content te voir (instead of Je suis content de te voir)

3. Pronoun Placement: When using object pronouns, they precede the infinitive:

• Je suis heureux de vous rencontrer (I’m happy to meet you)

4. Compound Tenses: With auxiliary verbs, the structure remains the same:

• J’ai été surpris d’entendre cette nouvelle (I was surprised to hear this news)

Common Mistakes to Avoid

1. Confusing de and à:

• Incorrect: Content à voir
• Correct: Content de voir

2. Omitting de in formal writing:

• Incorrect (formal): Important faire
• Correct: Important de faire

3. Misplacing pronouns:

• Incorrect: Heureux de te voir vous
• Correct: Heureux de vous voir