Devoir (must/to have to) also expresses probability or supposition:
Ils ne sont pas venus comme
prévu; ils doivent être malades.
(They did not come as planned; they must be/they probably are
sick.)
Probability can also be expressed with the use of the following impersonal expressions:
Il est probable
que (it is probable that)
il est fort probable que (it is very probable
that)
c'est probable (it is probable)
Est-il
probable qu'ils soient à la réunion? Oui, c'est fort
probable.
(Is it likely/probable that they will be at the meeting? Yes, it
is quite likely.)
See Also: