devoir/falloir

What’s the difference between devoir and falloir?

Sometimes it can be tricky to tell the difference between the verbs devoir and falloir. One talks about an obligation that is usually more personal, whereas the other talks about a necessity that is more universal. Read on to learn which is which, then put your knowledge to the test in the exercises.

Example

C’est le chaos dans le bureau de Jean.

« Il faut que je range tous ces dossiers avant l’arrivée de mes collègues ! », pense-t-il.

Tout d’abord, Jean doit classer les dossiers par ordre alphabétique. Il lui faudrait de l’aide. Heureusement, son ami Matthieu va passer pour lui donner un coup de main.

devoir vs. falloir

In broad terms, devoir and falloir are comparable to the English verbs have to and must. Both verbs refer to obligations, although devoir is usually used for personal obligations, while falloir refers to a more general or objective obligation and therefore appears in more formal contexts. In addition, they have different grammatical rules that we need to bear in mind.

devoir

When it is followed by a verb in the infinitive, devoir expresses an obligation.

Example:
Carine doit se réveiller à 6h30 tous les matins pour aller travailler.Carine has to get up at 6.30am every morning to go to work.

When devoir is conjugated in the conditional, it is similar to should; it expresses a supposition or a deduction.

Example:
Ils devraient arriver d’une minute à l’autre.They should be here any minute now.

When devoir is followed by a noun (not an infinitive), it means owe. In this case, we use the following structure: devoir quelque chose à quelqu’unto owe something to someone.

Example:
N’oublie pas que tu me dois vingt euros.Don’t forget that you owe me twenty euros.

falloir

The verb falloir expresses that something is a necessity. It has a similar meaning to devoir, but it is more formal and often expresses a need that is objective rather than subjective.

Falloir is an impersonal verb, which means that it can only be conjugated in the 3rd person singular with the subject pronoun il. It can be conjugated in every tense (il faut, il a fallu, il faudra, il faudrait, etc.).

Falloir can be followed by different grammatical structures, each of which change its meaning:

  • falloir + infinitive

Given that falloir is an impersonal verb, when it is followed by a verb in the infinitive, it describes something necessary that applies to a whole group of which the speaker is part (like the pronoun nous). This means that we cannot use falloir + infinitive to talk about separate individuals or groups that the speaker is not part of.

Examples:
Il faut rentrer avant le dîner.We have to be back before dinner.
(= Nous devons rentrer avant le dîner.)
Il fallait traverser le fleuve pour atteindre le village.We had to cross the river to reach the village.
(= Nous devions traverser le fleuve pour atteindre le village.)
  • falloir que + verb in the subjunctive

When we use a subordinate clause with falloir, it is introduced by que and the verb is always in the subjunctive. In this case, falloir remains an impersonal verb, however the verb in the subordinate clause can be conjugated in any person (in the subjunctive).

Examples:
Il faut que tu sois rentré chez toi avant le dîner.You have to be home before dinner.
Il fallait que je traverse le fleuve pour atteindre le village.I had to cross the river to reach the village.
  • falloir + noun

When falloir is followed by a noun, we must use an indirect object pronoun (me, te, lui, nous, vous, leur) directly before falloir. In this case, falloir means to need something.

Examples:
Il me faut un stylo et un bout de papier.I need a pen and a piece of paper.
(= J’ai besoin d’un stylo et d’un bout de papier.)
Il vous faudra beaucoup de courage pour réussir cette épreuve.You need a lot of courage to pass this test.
(= Vous aurez besoin de beaucoup de courage pour réussir cette épreuve.)

To learn the conjugations of devoir and falloir, check out our French Verbs Conjugator. To learn about some more pairs of confusing verbs, take a look at our pages on amener/emmener and aller/venir.