Impersonal expressions (il faut, il est important de)
Advice and obligation without naming who is obliged. The subject is always il, and it refers to nothing at all — the same empty il as il pleut.
| il faut + infinitive | one must, you need to |
|---|---|
| il ne faut pas + infinitive | one must not |
| il vaut mieux + infinitive | it is better to |
| il est important de + infinitive | it is important to |
| il est nécessaire de + infinitive | it is necessary to |
| il est possible de + infinitive | it is possible to |
Worked examples:
- Il faut boire beaucoup d'eau.
- Il vaut mieux se reposer deux jours.
- Il est important de manger à des heures régulières.
- Il ne faut pas rester debout toute la journée.
*The one that catches everyone: il ne faut pas means "must not", not "need not". Il ne faut pas fumer is a prohibition. To say something is unnecessary, French uses a different phrase entirely: ce n'est pas nécessaire or vous n'êtes pas obligé de*.
*Note the de. Il faut takes the infinitive bare — il faut partir — but the il est + adjective family needs de before it: il est important de partir. Missing that de* is the most frequent error with this structure.
In speech il faut is usually heard as faut: faut y aller. Recognise it; write the full form.
These expressions have a subjunctive form (il faut que vous partiez) which week 25 introduces. Until then, infinitive only.
What this unlocks
Knowing the rule is not the same as producing it.
This page explains the pattern. The track drills it: the point arrives inside a mini-dialogue, then production marked against a CEFR descriptor, then a module test that returns you to your two weakest sessions if you miss it.