Nightmare

Il mangeait en conduisant
To say things like while sleeping or while working in French, use en, followed by a verb ending with ‑ant!
En sortant, j'ai vu mon voisin.
While going out, I saw my neighbor.
Je me réveille trop tard
When you use a verb like se réveiller or se lever, remember to change se based on the person doing the action.
J'ai regardé l'horloge en me réveillant.​
I looked at the clock upon waking up.​
Elle n'a pas encore fini
If something hasn't happened yet, use the phrase ne... pas encore.
Ils n'ont pas encore appelé.
They have not yet called.
Elles ne sont pas encore parties.
They haven't left yet.​
Notice that you separate ne from the other words, but pas and encore always go together!
Nous n'avons pas encore vu le film.
We haven't seen the movie yet.