Falloir

Falloir is an irregular French verb which can be translated as ‘to be necessary’. It’s an impersonal verb, which means we only use it in the third person singular: il.

The exact meaning of falloir changes depending on whether it’s followed by another verb (infinite or subjunctive) or a noun. In all cases the subject is the impersonal ‘il’, but when followed by an infinitive verb or a noun you can also sometimes use an indirect object pronoun before falloir to specify who needs to do something. Without this, the ‘who’ is implied by the context.

Falloir + infinitive

Il fallait partir tôt - It was necessary to leave early

Il me faut attendre - I have to wait

Il leur a fallu attendre une heure - They had to wait an hour

Falloir + que + subjunctive

Il faut que nous partions - We have to leave

Il a fallu que nous changions d'hôtel - We had had to change hotels

Il fallait que tu sois prudent - You had to be careful

Falloir + noun

Il fallait plus de temps - More time was needed

Il me faut un café - I need a coffee

Il lui fallait une voiture - He/She needed a car

Falloir is an impersonal verb, and when referring to necessity, it can only be used in the ways outlined above.

Devoir and avoir besoin de, on the other hand, are not impersonal verbs. They are irregular verbs which conjugate according to the tense, person and number of their subject.

Devoir can be used for obligation, advice or probability, and can be translated as ‘need’, ‘ought’ or ‘must’:

Tu dois finir ce travail - You must finish this work

Il doit être chez lui - He is probably at home

Avoir besoin de most often translates simply as to ‘need’

J'ai besoin d'eau - I need water

Nous avons besoin d'aide - We need help

For more on the difference between devoir and avoir besoin de, check out our blog.