descendre: why is is descendaient for one example and descendraient for the other? Both are "they got off"

Question

Accepted Answer

Hi Maeve, 
I have checked and I can't find descendraient ( conditional of descendre) in the lesson,  I can, however, find a past historic or passé simple in French.
Les passagers descendirent du Titanic sains et saufs = The passengers got off the Titanic, safe and sound 
Take a look at the following lesson on how the past historic is used -
Passé simple
and how to conjugate verbs like descendre -
https://french.kwiziq.com/revision/grammar/conjugate-regular-dre-verbs-in-le-passe-simple
Bonne Continuation!

Answer

Please quote the entire sentences in question. I can't find "descendraient" anywhere in the lesson under question.