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Je dois y retourner à cinq heures.
1. I must go back there at five o'clock.
2. I must return there at five o'clock.
3. I am supposed to go back there at five o'clock.
4. I suppose that I'll return there at five o'clock.
Il devait arriver aujourd'hui, mais il n'est pas encore arrivé.
1. He had to arrive today, but he hasn't yet arrived.
2. He was supposed to arrive today, but he has not yet arrived.
Vous devriez vous tenir debout.
1. You ought to remain standing.
2. You should stay on your feet.
3. You will have to remain standing.
Vous ne devriez pas vous tenir debout.
1. You would not have to stay on your feet.
2. You should not remain on your feet.
3. You ought not remain standing.
Il a dû s'égarer car il n'est pas revenu.
1. He was supposed to lose his way for he hasn't come back.
2. He had to have lost his way for he did not come back.
3. He must have gotten lost for he hasn't come back.
Nous devrons travailler ce soir.
1. We should study tonight.
2. We must study tonight.
3. We will have to study tonight.
Vous ne devez pas parler français ici.
1. You don't have to speak French here.
2. You must not speak French here.

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