L'expression de l'obligation et de l'absence d'obligation
Exprimer l'obligation
Il existe plusieurs façons d'exprimer l'obligation en anglais selon le temps utilisé.
Au présent
- Must + base verbale
"You must be quiet !"
- Have to + base verbale
"I have to leave now."
- Have got to + base verbale
"They've got to move their car."
Au futur et au passé
On emploie will have to pour le futur et had to pour le passé.
Exemples- "You'll have to move if you get this job." (futur)
- "They had to borrow money to pay for their house." (passé)
Attention ! Mustn't exprime l'interdiction et non l'absence d'obligation.
Exemple"You mustn't make noise" = tu ne dois pas faire de bruit. (C'est interdit.)
Exprimer l'absence d'obligation
Pour exprimer l'absence d'obligation (ce qu'on n'est pas obligé de faire), on utilise différentes structures selon le temps.
Au présent
- Don't have to + base verbale
"You don't have to rush. You've got plenty of time."
- Needn't + base verbale
"You needn't rush. You've got plenty of time."
Au futur
- Won't have to + base verbale
"You won't have to get up early, we are leaving at 10."
Au passé
- Didn't have to + base verbale
"I didn't have to pay for the entrance. It was free."
Attention : needn't have + participe passé = tu n'aurais pas dû.
Exemple"You needn't have brought me flowers" (= tu m'as apporté des fleurs, mais ce n'était pas nécessaire.)