in one's sleep
Je t'ai entendu parler en dormant cette nuit.
I heard you talking in your sleep last night.
Elle a guéri sa gueule de bois en dormant.
She cured her hangover by sleeping.
On pourra veiller sur lui en dormant.
We can watch over him while we sleep.
— Parasite (2019)
Elle parle en dormant.
She talks in her sleep.
— Indiana Jones et la dernière croisade (1989)