Learn French: Au lieu de partir, il reste. - Instead of leaving, he stays.

In English, we say 'instead of leaving' using an -ing word. But in French, when a verb follows a preposition like de (or à, pour, sans), it must be in the infinitive form (the dictionary form, like partir). This ties into your current lesson: just like in il est important de partir, the de always links to an infinitive!

Does il reste mean 'he rests'?

No, rester is a classic false friend. It looks like 'to rest', but it actually means 'to stay' or 'to remain'. If you wanted to say 'he rests', you would use the verb se reposer (il se repose).

Is au lieu de a fixed phrase?

Yes! Au lieu de means 'instead of' or 'in place of'. The word lieu literally means 'place' (which is where we get the English phrase 'in lieu of'). It is always followed by a noun or an infinitive verb.

How does this relate to the impersonal expressions (like Il est bon de...) from this lesson?

While this sentence does not use an impersonal 'It is...' expression, it reinforces the exact same grammatical rule. Whether you say Au lieu de partir (Instead of leaving) or Il est difficile de partir (It is hard to leave), the preposition de forces the next verb to stay in its full infinitive form.