les efforts ont été vains
Their efforts were in vain.
Leurs efforts furent vains.
All our efforts were in vain.
Tous nos efforts ont été vains.
Our efforts were in vain.
Nos efforts ont été vains.
— The Thief (1997)
Her efforts were in vain.
Ses efforts furent vains.
My efforts were in vain.
Mes efforts furent vains.