had to, was necessary
Combien t'a-t-il fallu payer pour les billets ?
How much did you have to pay for the tickets?
Combien vous a-t-il fallu payer pour les billets ?
How much did you have to pay for the tickets?
Combien de temps vous a-t-il fallu pour traduire le livre ?
How long did it take you to translate the book?
Il nous a fallu trois mois pour assassiner l'ancien chef.
It took us three months to assassinate the former leader.
— Le Secret des poignards volants (2004)
Tu avais déjà une jolie fille mais il t'en a fallu une autre.
You already had a pretty girl, but you had to have another one.
— Picnic (1955)
Il m'aurait fallu plus de temps.
I would have needed more time.
Combien de temps t'a-t-il fallu pour décorer ton sapin de Noël ?
How long did it take you to decorate your Christmas tree?