Breakdown of La troupe se sera repliée avec la bannière.
être
to be
avec
with
la troupe
the troop
se replier
to retreat
Questions & Answers about La troupe se sera repliée avec la bannière.
Why does a future tense verb (se sera repliée) translate to a past tense assumption ("must have retreated")?
This is the epistemic use of the future perfect, often called the futur de probabilité. In French, you can use the future perfect to express a strong suspicion or deduction about a past event. While English uses "must have" plus the past participle, French achieves this by putting the verb in the future perfect.
Why does this sentence use sera instead of aura for the future perfect?
The verb used here is se replier (to fall back or retreat), which is a reflexive verb. Just like in the passé composé, all reflexive verbs use être as their auxiliary in the future perfect. Therefore, we use sera instead of aura.
Why is there an extra e at the end of repliée?
Could I say a dû se replier instead of se sera repliée to mean the same thing?
Yes! La troupe a dû se replier is another very common way to say "The troop must have retreated." Using the future perfect (se sera repliée) sounds slightly more literary or formal, but both convey the exact same sense of deduction about a past event.