could not
I couldn't help laughing.
Je ne pus entrer car la porte était fermée.
I couldn't get in because the door was closed.
Les enfants faisaient tant de bruit que je ne pus étudier.
The children were making so much noise that I couldn’t study.
Je ne pus me tenir debout plus longtemps.
I could not stand any longer.
Je ne pus pas saisir ce qu'il disait.
I couldn't make out what he was saying.
Je ne pus le convaincre de son erreur.
I could not convince him of his mistake.