Learn French: Nous sommes restés dehors.

In French, most verbs use avoir (to have) for the past tense, but a special group of verbs uses être (to be) instead. These are mostly verbs of motion or a change of state. Rester (to stay) belongs to this group. So, instead of saying 'we have stayed', the French literally say 'we are stayed'.

Why is there an 's' at the end of restés?

When you form the past tense with être, the past participle (here, resté) has to agree with the subject, just like an adjective. Since Nous (we) is plural, we add an 's' to make it restés. If 'we' referred to a group of entirely women, it would be restées.

Wait, doesn't rester mean 'to rest'?

That is a very common trap! Rester is a 'false friend.' It looks like the English word 'rest', but it actually means 'to stay' or 'to remain.' If you want to say 'to rest' in French, you use the verb se reposer.

Are the 'h' and 's' in dehors silent?

Yes, both the 'h' and the 's' are silent. You pronounce it roughly like 'duh-or.' Also, because dehors is an adverb (a word describing where an action happens), its spelling is locked. It never gets an extra 's' for plural, even though Nous is plural.