French language Q&A Forum

I seems to me that in most circumstances "attendre que + subjunctive" means "to wait until" and "jusqu'à ce que" is unnecessary. I asked this a few days ago and stil have not had a reply, so I checked in both Grevisse & Wartburg/Zumthor. They agree with me and even say the simple "que" is better.

Is it not a hard rule that verbs take être when followed by a preposition? In this phrase, I used avoir, which was wrong but there is no preposition that I can see: Quand vous y (êtes or avez) retourné, le corps avait disparu. Seems like retourner is followed by a noun. I use this method to determine quickly which auxiliary to use so would like to know if there are exceptions. Many thanks. 

In the exercise, the meaning of "Il aurait adoré la rencontrer" is given as "He would have loved meeting her". Am I correct in assuming that it can also be translated as "He would have loved to meet her"? In the first instance, in English, the implication is that he actually did meet her, but the second means that he hadn't met her at the time.

To go further, would "He would have loved to have met her" be translated as "Il aurait adoré l'avoir rencontrée"? Is this idiomatic?

Why is “the best answer” given as “Mes parents seront trop impressionnées”? Doesn’t the “ées” imply that both parents are female?

Also, could “impressionnant” be used instead of “impressionnés”? What would be the difference in meaning?