how
Comment le pourrais-tu, alors que tu ne m'as rien dit ?
How could you, when you didn't tell me anything?
— Mon cœur est déjà pris (1999)
What would you think of him?
How does he do it?
How do we know?
Comment le lui aurais-je promis puisque je suis marié.
How could I have promised him that since I'm married?
— Guerre et Paix (1968)
How are you taking it?