Subjunctive with Verbs of Necessity and Obligation
The French subjunctive appears after verbs that express necessity, obligation, or duty. Common triggering verbs include il faut que (it is necessary that), falloir, exiger (to demand), and interdire (to forbid). This grammar structure is essential for expressing what someone must do.
The subjunctive follows verbs of necessity and obligation like il faut que, falloir, and exiger to express required or compulsory actions. The main clause subject and subjunctive clause subject must be different.
Step-by-step worked examples
Il faut que tu fasses tes devoirs. (It is necessary that you do your homework.)
Main clause: Il faut (impersonal, third person) Subjunctive trigger: necessity verb Subjunctive clause: que tu fasses (you + present subjunctive of faire)
L'employeur exige que les employés arrivent à l'heure. (The employer demands that employees arrive on time.)
Main clause: L'employeur exige (employer demands) Subjunctive trigger: exiger (to demand) Subjunctive clause: que les employés arrivent (they + present subjunctive of arriver)
Il est nécessaire que vous participiez à la réunion. (It is necessary that you participate in the meeting.)
Main clause: Il est nécessaire (it is necessary) Subjunctive trigger: necessity expression Subjunctive clause: que vous participiez (you formal + present subjunctive of participer)
Flashcards
Quick quiz
Q1.Which verb form completes: Il faut que nous ___ avant minuit?
Q2.Does 'Je veux que tu viennes' use subjunctive?
Q3.Il faut que vous ___ les règles. (follow)
Q4.Which does NOT trigger subjunctive?
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Common mistakes
Il faut que je vais. (I faut that I go—wrong mood) — Correct: Il faut que j'aille. (It is necessary that I go—subjunctive)
L'employeur exige que tu viens. (Mixing present indicative) — Correct: L'employeur exige que tu viennes. (Present subjunctive)
Using infinitive when subjects differ: 'Il faut partir tôt.' (ambiguous for 'someone else must leave') — Correct: Il faut que tu partes tôt. (He/She must leave early—with subjunctive)
Forgetting que: 'Il faut tu fasses.' (Missing conjunction) — Correct: Il faut que tu fasses. (The conjunction 'que' is required)
FAQ
What is the difference between necessity and permission?
Necessity (il faut que, exiger, interdire) triggers subjunctive. Permission (pouvoir, permettre) typically uses indicative or infinitive depending on context.
Must subjects be different for necessity + subjunctive?
Yes. If the same person is the subject, use infinitive: Je dois partir (I must leave). If different: Je veux que tu partes (I want you to leave—subjunctive).
Is il est nécessaire que always subjunctive?
Yes. Any expression of necessity (il est nécessaire que, il faut que, il est indispensable que) requires subjunctive in the dependent clause.
What about irregular subjunctive forms?
Common irregulars: être (sois, soyons), avoir (aie, ayons), aller (aille, allions), faire (fasse, fassions). They follow in subjunctive contexts after necessity verbs.