Devoir Conjugation in French: Complete Tense Guide and Tables

The French verb devoir is one of the most critical modal verbs you will encounter. Translating roughly to must, to have to, should, or to owe, it appears in almost every everyday conversation. However, because it belongs to the irregular third group (3e groupe), its conjugations change considerably from one tense to another.

In this comprehensive guide from my-french.com, you will find full conjugation tables, pronunciation insights, meaning variations, and common pitfalls to avoid.

1. Present Tense (Présent de l'indicatif)

In the present tense, devoir splits between two stem bases: doi- (for singular subjects and ils/elles) and dev- (for nous and vous).

Pronunciation Tip

Subject Pronoun Conjugation English Equivalent
:--- :--- :---
Je dois I must / I have to
Tu dois You must / You have to
Il / Elle / On doit He / She / One must
Nous devons We must / We have to
Vous devez You must / You have to (formal/plural)
Ils / Elles doivent They must / They have to

Je dois, tu dois, and il doit are all pronounced identically: /dwa/. The final -s and -t are silent. Ils doivent is pronounced /dwav/.

2. Past Tenses: Passé Composé vs. Imparfait

Choosing between the passé composé and the imparfait of devoir completely changes your sentence's meaning.

Passé Composé

Auxiliary: avoir Past participle: dû
  • J'ai dû
  • Tu as dû
  • Il / Elle / On a dû
  • Nous avons dû
  • Vous avez dû
  • Ils / Elles ont dû
  • J'ai dû partir tôt. = I had to leave early (and I actually left).
  • Il a dû oublier son téléphone. = He must have forgotten his phone.

    • Meaning: Expresses a completed necessity or a deduction about an event that definitely occurred.

    Imparfait

Stem: dev- + imperfect endings (-ais, -ais, -ait, -ions, -iez, -aient).

  • Je devais
  • Tu devais
  • Il / Elle / On devait
  • Nous devions
  • Vous deviez
  • Ils / Elles devaient
  • Je devais partir à huit heures. = I was supposed to leave at 8:00 (it was the plan, but maybe I didn't).

    • Meaning: Expresses an unfulfilled intention or what was supposed to happen.

    3. Future & Conditional Forms

Both the future simple and the conditional share the irregular stem: devr-.

Futur Simple

  • Je devrai (I will have to)
  • Tu devras (You will have to)
  • Il / Elle devra (He/She will have to)
  • Nous devrons (We will have to)
  • Vous devrez (You will have to)
  • Ils / Elles devront (They will have to)

    • Used for future obligations:

Example: Vous devrez présenter votre passeport à l'embarquement. (You will have to show your passport upon boarding.)

Conditionnel Présent

  • Je devrais (I should)
  • Tu devrais (You should)
  • Il / Elle devrait (He/She should)
  • Nous devrions (We should)
  • Vous devriez (You should)
  • Ils / Elles devraient (They should)

    • This form translates directly to "should" or "ought to" in English. It softens commands and provides polite advice:

Example: Tu devrais consulter un médecin. (You should see a doctor.)

Conditionnel Passé (Past Conditional)

  • J'aurais dû = I should have
  • Tu aurais dû m'appeler. = You should have called me.

    • Formed with avoir in the conditional + dû:

    4. Subjunctive Present (Subjonctif Présent)

Required after expressions of necessity, doubt, or subjective judgment:

Subject Pronoun Subjunctive Form
:--- :---
Que je doive
Que tu doives
Qu'il / elle / on doive
Que nous devions
Que vous deviez
Qu'ils / elles doivent

Example: Bien qu'elle doive travailler ce week-end, elle garde le sourire. (Even though she has to work this weekend, she remains cheerful.)

5. The Core Meanings of Devoir

To master devoir, always identify which function it fulfills in the sentence:

1. Obligation / Necessity: Followed by an infinitive (Je dois payer le loyer = I must pay the rent).

2. Probability / Deduction: (La lumière est allumée, il doit être chez lui = The light is on, he must be home).

3. Indebtedness / Owing: Followed by a noun (Combien est-ce que je vous dois ? = How much do I owe you?).

4. Intended Action: (Je dois le voir demain = I am to see him tomorrow).

Key Takeaway: The Circumflex on « Dû »

Remember to write dû with a circumflex accent in the masculine singular past participle (j'ai dû). This distinguishes it from the partitive article du (du fromage).

  • La somme due (The amount due)
  • Les devoirs dus (The owed assignments)

    • However, when made feminine or plural, the circumflex disappears because no ambiguity exists:

Keep this guide handy, practice with real-life sentences, and you will navigate the nuances of devoir with confidence!